User:Timothy2b/sandbox

Ituval fictional climate
Ituval has a humid continental climate (Dfa) according to the Köppen climate classification, with large seasonal differences. Summers are hot and humid, with July daytime temperatures of 27 to 30 C, though lake breeze helps moderate humidity. Nighttime temperatures are pleasantly cool, hovering around 14 to 18 C, but they may drop to about 10 C on cool nights. Heatwaves occur each summer, pushing highs into the mid-to-high 30s, and there is on average one day a year that reaches 40 C. Nights offer little relief under these conditions, as the city experiences "tropical nights" with temperatures above 20 C. On average, 29 days a year reach 30 C or higher. Thunderstorms often put an abrupt end to heatwaves, and, while a welcome end to the heat, may generate very heavy rainfall.

Winters are cold and snowy, with January highs of -3 to -7 C. Nighttime temperatures range from -8 to -14 C, though may fall to -20 C on cold, clear nights. Thaws may occur a few times each winter when daytime temperatures rise to 2 to 5 C, but nights remain below freezing. Conversely, the mercury fails to reach 0 C on an average of 89 days a year. Cold snaps occur 2 to 3 times each winter when the polar vortex dives south, bringing frigid conditions when daytime temperatures may struggle to rise above -15 C or even -20 C. The temperature falls to -20 C or lower on an average of 8 nights a year. The coldest temperature of the year tends to fall to between -25 and -30 C. Lake Iquoia begins to freeze along the shore in late November, while the deeper open waters tend to remain open until mid-January. Ice breakup occurs in March. Snow cover typically lasts from late November to mid-March.

Spring and fall are relatively short transitional seasons, bringing mild, albeit variable, weather with pleasant days and cool nights. Spring arrives in early-mid March and is the driest period of the year. As the snow melts and night frosts cease, nature rapidly begins to bloom toward the end of the month, with trees leafing out during the second week of April. The Cherry Blossom Festival is a popular event at this time, occurring from late March to mid-April. Spring lasts until mid-to-late April when summer arrives, though nights remain cool or cold through mid-May. Fall arrives in mid-October, and is popular among tourists visiting for the Indian summer. Fall foliage can be seen from late September to early November, usually peaking in mid-October. The maples, dogwoods, hickories, and sumacs mark a vibrant end to the growing season and have given the city a reputation as one of fall's most colorful in the Western hemisphere. Winter then arrives in mid-November.

The highest temperature ever recorded was 43.5 C on July 18, 1998, while the hottest month on record was July 1976 with a daily mean of 26.8 C. The highest daily minimum of 31.3 C occurred on August 5, 2006, on the same day as the August record high. The coldest temperature recorded was -41.1 C on January 18, 1937, during the coldest month on record which had a mean of -18.9 C. The lowest daily maximum was -31.8 C on December 22, 2009. The longest streak when the temperature failed to rise above 0 C was 115 days from November 16, 2010 to March 10, 2011. The longest streak of consecutive highs above 30 C was 27 days from July 14 to August 9, 1997.

Precipitation amounts to 752 mm a year and is relatively evenly distributed throughout the year, though there is a noticeable dip in spring. Summers are subject to both torrential rainfall during thunderstorms as well as droughts, though these tend not to be severe. Snowfall averages 222 cm a year and is concentrated from November to February, with some snow also falling in March. In some years, snowfall may also occur in October and, more rarely, April. Ituval is sometimes subject to lake-effect snow, especially between November and January when winds most commonly blow from the lake. The highest snowfall in a day was 76 cm on December 6, 2009 during a lake-effect event. The snowiest season on record was 1986–1987 with 283 cm. Snow depth tends to reach a peak of just under 90 cm in mid-February before the spring thaw sets in. The deepest snow depth on record was 227 cm on March 15, 2019, following an very snowy start to the winter season in November, successive lake-effect events, and a very cold March. The longest continuous snowcover was 165 days from October 28, 1941 to April 10, 1942. Ituval enjoys many sunny days, and averages 2756 sunshine hours a year.

With the geomagnetic north pole tipped quite significantly in its direction, the aurora borealis is not an uncommon sight on clear winter nights in Ituval, despite being located at 50° latitude.

Seasonal averages:

Temperature progression over the course of the year.

Gulf Stream collapse
Helsingborg has a humid continental climate (Dfa) according to the Köppen climate classification, the only Swedish city qualifying as having the hot-summer variant. Summers are warm to hot and sunny, the hottest and longest in Sweden, with daytime temperatures typically hovering between 25 and 28 C. Nights are pleasantly cool, ranging from 14 to 18 C, though the coolest nights may fall to around 10 C. Cooler periods occur with highs of 20 to 24 C and lows in the 10 to 14 C range, and this is typically when the city receives most of its summer rainfall. Meanwhile, heatwaves typically feature highs of 30 to 35 C with dry, sunny weather, which often leads to drought conditions, though at times this may also lead to thunderstorms. There are 76 "högsommardagar" (high/peak summer days) annually when the temperature rises above 25 C, with daytime highs reliably staying above 20 C from late May through mid-September. Highs reach 30 C on an average of 17 days a year, with the hottest days around 35 C. Due to maritime moderation, "tropical nights" are a common occurrence during heatwaves, with nighttime temperatures remaining above 20 C. Sea surface temperatures range from around 15 C in early June to 24 C by the end of August.

Winters are cold and snowy, though short by Swedish standards, with daytime highs between -3 and -6 C. Nighttime temperatures usually hover between -9 and -12 C, though regularly fall to -15 to -18 C. Thaws may occur a few times per winter, but only last for a few days, with highs reaching 1 to 3 C. Conversely, cold snaps occur a couple of times per winter, with clear weather and daytime temperatures below -10 C on 15 days annually. There are on average 6 nights a year with lows below -20 C, with the coldest typically being around -25 C. Temperatures below -30 C are rather rare, occurring on average once or twice a decade. Highs can generally be expected to remain below the freezing mark from late November to early March, with an average of 100 such days a year. Snow cover usually lasts from late November to late March. Sea ice formation begins in early December, and grows continuously throughout the winter. By early-mid January, the Öresund strait has frozen across, and in late January ice roads open for traffic to Helsingør. Ice breakup takes place from mid-March to mid-April.

Spring and fall are relatively short transitional seasons, with variable weather conditions. Helsingborg is, on average, the first city to receive meteorological spring in Sweden, and among the last to receive meteorological fall. Spring begins during the second half of March, accompanied by the spring thaw and sea ice breakup. April features a somewhat moderated version of the infamous Swedish "aprilväder" (literally "April weather") with at times large swings in temperature that can feature summer-like weather one day and snowfall the next. Some spring days may also feature thick fog along the coast, caused by warm, moist air traveling over the lingeringly cold ocean. This may cause large temperature contrasts on land over very short distances, with coastal locations having 5 C and fog while the weather is sunny with 15 C less than a kilometer inland. Trees begin to leaf out toward the end of April, roughly coinciding with the arrival of meteorological summer. May then marks the transition from spring to summer weather. Due to warm ocean waters in the late summer, as well as its relative proximity to continental Europe, Helsingborg retains average highs above 20 C through September, a rarity in Sweden unique to the coastal plains of Skåne. Additionally, it is one of only two Swedish cities never to have recorded a freeze in September, the other being Lund. Fall arrives in mid-October and features many rainy days and, unlike spring, is characterized by a more steady decline in temperatures. However, some years summer warmth may persist for a week or two into October, while others could even see the first snowfall occur at the end of the month. Fall foliage can be seen from early October to early November. Winter then arrives in mid-November, often during a prolonged period of late-fall freeze-thaw cycles, referred to by locals as "slaskveckorna" ("the slush weeks").

The highest temperature recorded in Helsingborg was 38.4 C on July 16, 2002, and July 28, 2018. Readings of 38 C have occurred on many dates in both July and August, but due to maritime moderation temperatures have not risen much higher than that benchmark. This is in spite of an average annual record high of 34.9 C, a mere 3.5°C lower than the all-time record. 2018 also featured the hottest month on record, with July that year having a daily mean of 26.1 C, as well as the longest continuous streak of temperatures above 30 C, at 36 days from July 9 to August 13. The highest daily minimum was 26.2 C on August 3, 1975, on the same day as the August record high. The coldest temperature recorded was -41.0 C on January 23, 1966, which coincided with the lowest daily maximum at -35.6 C. The coldest month was January 1987, with a daily mean of -17.7 C, and the longest streak during which the temperature failed to rise above freezing was 123 days from November 28, 1941, to March 30, 1942.

Annual precipitation amounts to 427 mm, rather dry for a city on the west coast, with the wettest period in the fall and early winter and fairly dry conditions in spring and summer. Flooding is associated with the spring thaw, but is rarely a problem along the coast as meltwater naturally flows out into the sea. Droughts are much more frequent, and can be severe during prolonged summer heatwaves, forcing water restrictions to be put in place. Snowfall averages 162 cm a year and is concentrated from November to March. At least one day with snowfall can be expected in April, while it is rare in October. Helsingborg is occasionally subject to ocean-effect snow when the wind blows from the northwest in the early winter while the sea is still open. The snowiest day on record saw 85 cm accumulate on December 10, 2009, while the snowiest season was 1998-1999 when 265 cm fell. Snow depth typically peaks at around 65 cm in late February or early March before the spring thaw begins. The deepest snow depth was 176 cm on March 18, 1999. The longest continuous snow cover was 166 days from November 3, 1941 to April 17, 1942.

Helsingborg features large variations in daylight over the course of the year, from a peak of 17 hours and 35 minutes on the summer solstice to 6 hours and 55 minutes on the winter solstice. The city enjoys a relatively sunny climate for a coastal location this far north, with an average of 2158 hours of sunshine a year.

Seasonal averages:

Seasonal tables

Other climate data

Gulf Stream collapse
Like most of central and southern Sweden, Uppsala has a humid continental climate (Dfb) according to the Köppen climate classification with vast seasonal differences. Summers are warm to hot, with long daylight hours and nights that never get truly dark. Daytime highs at this time typically hover in the 24 to 27 C range, sometimes reaching 30 C, and the weather is fairly sunny. Nights are cool, between 13 and 17 C, though may on cooler nights fall below 10 C. Rainy periods are usually accompanied by somewhat cooler temperatures, with highs of 20 to 23 C, and higher humidity. Conversely, heatwaves are dry and sunny with highs of 28 to 32 C, sometimes leading to extended droughts. "Högsommardagar" (high/peak summer days) occur 60 days annually, while highs reach the 30 C-mark on 13 days, the hottest around 33 C. Overall, highs above 20 C can typically be expected from early June through the end of August.

Winters are long, snowy, and very cold, spanning five months, with highs of -6 to -9 C. Nighttime temperatures typically range from -12 to -16 C, though frequently fall to between -18 and -22 C. Occasional thaws do occur, once or twice per winter, though temperatures rarely rise higher than 1 or. Also, in some winters temperatures fail to rise above freezing altogether, with an average of 128 days with highs below 0 C, such being the norm from mid-November through mid-March. Cold snaps occur every winter and feature frigid conditions with daytime highs below -10 C and nights below -20 C, with that being the case on 25 and 18 days respectively. The coldest days often feature highs of around -20 C, with nighttime temperatures falling below -30 C or even -35 C. The Fyris river usually lies frozen from the second week of November until the beginning of April. A common tradition is ice skating on the first of Advent, as that typically coincides with when the last parts of the river freeze solid. Snow cover normally lasts from early November to mid-April.

Spring and fall are short transitional seasons with variable weather conditions. Spring begins in early April and is subject to extreme swings in temperature and weather, which in Sweden is known as "aprilväder" (literally April weather). Characterized by its unpredictability, April may feature near-summerlike temperatures one day, with snowfall the next. Weather conditions typically begin to stabilize at the end of April, with trees leafing out in early-mid May. Summer then arrives in mid-May. Fall arrives in late September and, unlike spring, usually sees a more steady decline in temperatures. Fall foliage can be seen from mid-September to late October. Marking the transition to winter is an at times prolonged period of freeze-thaw cycles dubbed "oktöber" and "tövember" (roughly Octhawber and Thawvember) for the slushy conditions characteristic of October and November in northern and central Sweden. Winter usually arrives in early November.

The highest temperature recorded in Uppsala was 40.4 C on July 19, 2018, which also saw the hottest month on record, with July having a mean temperature of 25.3 C. That summer also saw the longest streak of consecutive days above 30 C, with 24 days from July 13 to August 4. The highest daily low was 24.6 C on the same day as the June record high. The coldest temperature recorded was -51.5 C on January 22, 2021, the only time the temperature was sunk below -50 C. That day is also the only when the temperature remained below -40 C, peaking at -41.3 C. The coldest month was January 1987, with a daily mean of -23.7 C. The longest streak during which the temperature failed to rise above freezing was 157 days from October 30, 1941, to April 4, 1942.

Annual precipitation amounts to 525 mm and is higher in the summer and fall, and lower in the spring. The spring thaw leads to high water discharge in the Fyris river and may in some years lead to flooding in downstream locations, especially on cold nights as downstream ice accretion blocks water flow. Droughts also occur during prolonged heatwaves, though thanks to meltwater reservoirs, water supply is rarely, if ever, an issue. Snowfall averages 216 cm annually and is concentrated from November to March, though usually happens at least once in both October and April. Uppsala is often subject to lake-effect snow blowing off the Baltic Sea, especially in early winter before sea ice becomes widespread. Record snowfall occurred on November 7, 2006 when 67 cm accumulated over the course of 24 hours, during which some coastal locations in northern Uppland received over 150 cm. The snowiest season was 2009-2010 when 303 cm fell. Snow depth typically peaks at just under 90 cm before the spring thaw. The deepest snow depth was on March 27, 1966 with 231 cm. The longest continuous snow cover was 200 days from October 15, 1941, to May 2, 1942.

The aurora borealis can sometimes be seen from Uppsala.

Seasonal averages:

Temperature change across the seasons