Climate and monthly weather forecastCastalia, IA
Climate and monthly weather forecast
Weather in January
January, like December, is a freezing cold winter month in Castalia, Iowa, with an average temperature varying between 22.5°F (-5.3°C) and 9.9°F (-12.3°C). January, with its average high-temperature of 22.5°F (-5.3°C) and an average low-temperature of 9.9°F (-12.3°C), holds the record as the coldest month. Weather in January »Weather in February
February, the last month of the winter in Castalia, is another freezing cold month, with temperature in the range of an average high of 26.2°F (-3.2°C) and an average low of 13.1°F (-10.5°C). The beginning of February records an average high-temperature of a still freezing cold 26.2°F (-3.2°C), marking a negligible difference from January's 22.5°F (-5.3°C). Weather in February »Weather in March
March, the first month of the spring in Castalia, is a cold month, with an average temperature varying between 41.4°F (5.2°C) and 27°F (-2.8°C). March's arrival witnesses a distinct temperature rise, advancing from February's subzero cold 26.2°F (-3.2°C) to a wintry 41.4°F (5.2°C). Weather in March »Weather in April
April is a fresh spring month in Castalia, Iowa, with an average temperature varying between 54.3°F (12.4°C) and 37.9°F (3.3°C). Castalia, Iowa, experiences a temperature shift with the start of April, with average high-temperatures moving from an icy 41.4°F (5.2°C) in March to a cool 54.3°F (12.4°C). Weather in April »Weather in May
The last month of the spring, May, is a comfortable month in Castalia, Iowa, with an average temperature varying between 48.9°F (9.4°C) and 65.8°F (18.8°C). An upsurge in temperatures occurs as April gives way to May, with average highs shifting from a cool 54.3°F (12.4°C) to an enjoyable 65.8°F (18.8°C). Weather in May »Weather in June
The first month of the summer, June, is a warm month in Castalia, Iowa, with an average temperature fluctuating between 58.6°F (14.8°C) and 75.4°F (24.1°C). June's arrival signals an increase in average high-temperatures, moving from May's refreshing 65.8°F (18.8°C) to a warm 75.4°F (24.1°C). Weather in June »Weather in July
July, the same as June, is a moderately hot summer month in Castalia, Iowa, with an average temperature fluctuating between 79°F (26.1°C) and 62.2°F (16.8°C). Castalia's warmest month, July, generally records average temperatures ranging from a high of 79°F (26.1°C) to a low of 62.2°F (16.8°C). Weather in July »Weather in August
August, the last month of the summer in Castalia, is another warm month, with an average temperature varying between 77.5°F (25.3°C) and 59.5°F (15.3°C). The advent of August reveals an average high-temperature of a still moderately hot 77.5°F (25.3°C), showing minimal difference from the prior month. Weather in August »Weather in September
September, the first month of the autumn in Castalia, is still a pleasant month, with an average temperature ranging between min 52.3°F (11.3°C) and max 71.1°F (21.7°C). The advent of September brings a subtle shift in temperature, with the average high moving from a moderately hot 77.5°F (25.3°C) in August to an agreeable 71.1°F (21.7°C). Weather in September »Weather in October
October, like September, is another refreshing autumn month in Castalia, Iowa, with an average temperature ranging between max 57°F (13.9°C) and min 41.4°F (5.2°C). The onset of October introduces a moderate change in Castalia's weather, with average high-temperatures falling from September's pleasant 71.1°F (21.7°C) to a refreshing 57°F (13.9°C). Weather in October »Weather in November
The last month of the autumn, November, is another cold month in Castalia, Iowa, with temperature in the range of an average low of 29.5°F (-1.4°C) and an average high of 42.6°F (5.9°C). A distinct shift in the average high-temperature is signaled in November, moving down from a refreshing 57°F (13.9°C) in October to a cold 42.6°F (5.9°C). Weather in November »Weather in December
The first month of the winter, December, is also a subzero cold month in Castalia, Iowa, with an average temperature ranging between min 18.7°F (-7.4°C) and max 28.9°F (-1.7°C). As December begins, there is a decrease in the average high-temperature, falling from a wintry 42.6°F (5.9°C) in November to a subzero cold 28.9°F (-1.7°C). Weather in December »Updated: Jun 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Castalia's coldest month, January, registers temperatures that range from a high of 22.5°F (-5.3°C) to a low of 9.9°F (-12.3°C).
The most humid month is January, with an average relative humidity of 89%.
The month with the least rainfall in Castalia is January, when the rain falls for 4 days and typically collects 0.98" (25mm) of precipitation.
Throughout the year, there are 131 rainfall days, and 27.91" (709mm) of precipitation is accumulated.
January through May, October through December are months with snowfall.
In Castalia, during the entire year, snow falls for 52.3 days and aggregates up to 21.26" (540mm) of snow.
With an average of 3.5h of sunshine, January has the least sunshine of the year.
The months with the lowest UV index are January, November and December, with an average maximum UV index of 1.
February is the month with the most snowfall. Snow falls for 10.3 days and accumulates 5.16" (131mm) of snow.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Castalia, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.
June is the month with the most rainfall. Rain falls for 17.7 days and accumulates 4.33" (110mm) of precipitation.
In Castalia, snow does not fall in June through September.
With an average of 15h and 18min of daylight, June has the longest days of the year.
July proves to be the warmest month, recording an average peak temperature of 79°F (26.1°C) and a minimum temperature of 62.2°F (16.8°C).
July is the month with the highest UV index, with an average maximum UV index of 6.
The month with the most sunshine is August, with an average of 9.8h of sunshine.
The least humid month is October, with an average relative humidity of 75%.
The month with the shortest days is December, with an average of 9h and 6min of daylight.
Average temperature
Castalia, IA
The warmest month (with the highest average high temperature) is July (79°F).
The month with the lowest average high temperature is January (22.5°F).
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure
Castalia, IA
- Average pressure in January:
30.13"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.94"Hg - Average pressure in May:
29.94"Hg - Average pressure in June:
29.89"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
29.99"Hg - Average pressure in November:
30.08"Hg - Average pressure in December:
30.1"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed
Castalia, IA
- Average wind speed in January:
10.2mph - Average wind speed in February:
10.1mph - Average wind speed in March:
10mph - Average wind speed in April:
10.5mph - Average wind speed in May:
9mph - Average wind speed in June:
7.9mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity
Castalia, IA
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (75%).
Average rainfall
Castalia, IA
- Average rainfall in January:
0.98" - Average rainfall in February:
1.14" - Average rainfall in March:
1.69" - Average rainfall in April:
3.19" - Average rainfall in May:
3.78" - Average rainfall in June:
4.33"
- Average rainfall in July:
2.91" - Average rainfall in August:
2.01" - Average rainfall in September:
2.44" - Average rainfall in October:
2.52" - Average rainfall in November:
1.5" - Average rainfall in December:
1.42"
The wettest month (with the highest rainfall) is June (4.33").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days
Castalia, IA
- Average rainfall days in January:
4 days - Average rainfall days in February:
3.8 days - Average rainfall days in March:
10.1 days - Average rainfall days in April:
15.3 days - Average rainfall days in May:
17.3 days - Average rainfall days in June:
17.7 days
- Average rainfall days in July:
14.6 days - Average rainfall days in August:
12.3 days - Average rainfall days in September:
10.7 days - Average rainfall days in October:
11.6 days - Average rainfall days in November:
8.2 days - Average rainfall days in December:
5.4 days
The month with the highest number of rainy days is June (17.7 days).
The month with the least rainy days is February (3.8 days).
Average snowfall
Castalia, IA
The month with the highest snowfall is February (5.16").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Castalia, IA
- Average snowfall days in January:
13.3 days - Average snowfall days in February:
10.3 days - Average snowfall days in March:
7 days - Average snowfall days in April:
3 days - Average snowfall days in May:
0.3 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
1.4 days - Average snowfall days in November:
5.1 days - Average snowfall days in December:
11.9 days
The month with the highest number of snowfall days is January (13.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Castalia, IA
- Average daylight in January:
9h and 24min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 42min - Average daylight in June:
15h and 18min
- Average daylight in July:
15h and 0min - Average daylight in August:
13h and 54min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 42min - Average daylight in December:
9h and 6min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in January:
3h and 30min - Average sunshine in February:
3h and 42min - Average sunshine in March:
5h and 42min - Average sunshine in April:
7h and 18min - Average sunshine in May:
8h and 6min - Average sunshine in June:
9h and 12min
- Average sunshine in July:
9h and 36min - Average sunshine in August:
9h and 48min - Average sunshine in September:
8h and 54min - Average sunshine in October:
5h and 12min - Average sunshine in November:
5h and 0min - Average sunshine in December:
4h and 0min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days
Castalia, IA
- Average sunshine days in January:
15.3 days - Average sunshine days in February:
15.3 days - Average sunshine days in March:
15.4 days - Average sunshine days in April:
11.5 days - Average sunshine days in May:
12.3 days - Average sunshine days in June:
10.5 days
- Average sunshine days in July:
12.8 days - Average sunshine days in August:
16.4 days - Average sunshine days in September:
17 days - Average sunshine days in October:
16.6 days - Average sunshine days in November:
16.9 days - Average sunshine days in December:
16.8 days
The month with the most sunshine days is September (17 days).
The month with the least sunshine days is June (10.5 days).
Average UV index
Castalia, IA
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover
Castalia, IA
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility
Castalia, IA
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
