Climate Insights for Alton

Stanton County, Iowa, United States

Hottest
July
29°C peak
Coldest
January
-10°C low
Wettest
May
135mm rain
Best to Visit
July, September
Mild temps & low rain

Climate Overview

The climate in Alton is cool. The average annual temperature is 10°C and approximately 843mm of precipitation falls per year. May is the wettest month, receiving around 135mm of rainfall. Alton is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, June, August. The coldest months are January, February, December, when temperatures can drop to -10°C. Snowfall occurs from January to December, with around 72cm accumulating over the season.

Temperature

-10° 10° 20° 30° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Max: -2° Average: -6° Min: -10° Feb Max: 1° Average: -5° Min: -10° Mar Max: 9° Average: 3° Min: -2° Apr Max: 16° Average: 9° Min: 3° May Max: 22° Average: 16° Min: 11° Jun Max: 29° Average: 23° Min: 17° Jul Max: 29° Average: 24° Min: 19° Aug Max: 28° Average: 22° Min: 17° Sep Max: 26° Average: 19° Min: 14° Oct Max: 17° Average: 11° Min: 6° Nov Max: 9° Average: 3° Min: -1° Dec Max: 2° Average: -3° Min: -7°
Max
Average
Min

Alton has a wide annual temperature range, spanning 39°C from the coldest to warmest months. The warmest month is July, when average highs reach 29°C and the mean temperature sits around 24°C. The coldest month is January, when overnight lows fall to -10°C and the daily average is -6°C. On average, daily temperatures fluctuate by about 11°C between overnight lows and afternoon highs. The sharpest temperature change occurs between September and October, with a 9°C shift in average temperatures.

Precipitation

0mm 25mm 50mm 75mm 100mm 125mm 150mm Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Precipitation: 27mm Snow: 17mm Feb Precipitation: 27mm Snow: 14mm Mar Precipitation: 61mm Snow: 12mm Apr Precipitation: 96mm Snow: 6mm May Precipitation: 135mm Snow: 1mm Jun Precipitation: 109mm Snow: 0mm Jul Precipitation: 69mm Snow: 0mm Aug Precipitation: 103mm Snow: 0mm Sep Precipitation: 74mm Snow: 0mm Oct Precipitation: 64mm Snow: 1mm Nov Precipitation: 38mm Snow: 8mm Dec Precipitation: 39mm Snow: 13mm
Precipitation
Snow

Alton is a moderately rainy area, receiving approximately 843mm of precipitation annually, which averages out to around 70mm per month. The wettest month is May, averaging 135mm of rainfall. June and August also tend to see above-average precipitation. The driest month is February, with just 27mm. That's 109mm less than May, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Snowfall is a regular feature from January to December, with around 72cm accumulating over the season. January typically sees the most snow at around 17cm.

Wind

0km/h 5km/h 10km/h 15km/h 20km/h 25km/h 30km/h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Wind Speed: 23km/h Feb Wind Speed: 24km/h Mar Wind Speed: 25km/h Apr Wind Speed: 27km/h May Wind Speed: 23km/h Jun Wind Speed: 22km/h Jul Wind Speed: 19km/h Aug Wind Speed: 20km/h Sep Wind Speed: 22km/h Oct Wind Speed: 24km/h Nov Wind Speed: 23km/h Dec Wind Speed: 23km/h
Wind Speed

Alton is moderately windy, with an average annual wind speed of 23km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 27km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in July, with average winds dropping to 19km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 8km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 23km/h in winter, 25km/h in spring, 20km/h in summer, 23km/h in autumn.

Seasons

Winter
Dec 21
Spring
Mar 20
Summer
Jun 21
Autumn
Sep 23

88 days until Summer

It is currently spring in Alton, which began on March 20, 2026. Alton is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 29°C, while the coldest stretch bottoms out in January near -10°C. Summer is next, beginning on June 21, 2026 — 88 days from now.

Spring

Temperatures range from -2 to 22°C. Precipitation is moderate at around 293mm for the season, averaging 98mm per month. Winds are moderate at around 25km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.

Summer

Temperatures range from 17 to 29°C. Precipitation is moderate at around 281mm for the season, averaging 94mm per month. Winds are moderate at around 20km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.

Autumn

Temperatures range from -1 to 26°C. Precipitation is moderate at around 176mm for the season, averaging 59mm per month. Expect around 9cm of snow accumulation during this period. Winds are moderate at around 23km/h. Layered clothing works best as temperatures gradually cool — enjoy the crisp air and changing scenery.

Winter

Temperatures range from -10 to 2°C. Rainfall is relatively light, with around 93mm over the season and a monthly average of 31mm. Expect around 44cm of snow accumulation during this period. Winds are moderate at around 23km/h. Warm winter clothing and waterproof boots are a must, and travel may be affected by snow.

Best Time to Visit

Jan -6°
Feb -5°
Mar
Apr
May 16°
Jun 23°
Jul 24°
Aug 22°
Sep 19°
Oct 11°
Nov
Dec -3°

The best time to visit Alton is during July and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 22°C with modest rainfall averaging 72mm per month. By contrast, January can be quite cold with temperatures dropping to -10°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

Monthly Climate Data

The table below shows monthly climate averages for Alton based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.

Month
Min Temperature
Max Temperature
Wind Speed
Precipitation
Snow
Jan
-10 °C
-2 °C
23 km/h
27 mm
17 cm
Feb
-10 °C
1 °C
24 km/h
27 mm
14 cm
Mar Current
-2 °C
9 °C
25 km/h
61 mm
12 cm
Apr
3 °C
16 °C
27 km/h
96 mm
6 cm
May
11 °C
22 °C
23 km/h
135 mm
1 cm
Jun
17 °C
29 °C
22 km/h
109 mm
0 cm
Jul
19 °C
29 °C
19 km/h
69 mm
0 cm
Aug
17 °C
28 °C
20 km/h
103 mm
0 cm
Sep
14 °C
26 °C
22 km/h
74 mm
0 cm
Oct
6 °C
17 °C
24 km/h
64 mm
1 cm
Nov
-1 °C
9 °C
23 km/h
38 mm
8 cm
Dec
-7 °C
2 °C
23 km/h
39 mm
13 cm
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Metric (°C, km/h)