Casper, United States experiences average highs of 15°C (59°F) and lows of 2°C (36°F) throughout the year. The climate is relatively dry, with only 7 rainy days per month on average. Sunshine is abundant, averaging about 10 hours per day. Average highs have warmed by 1.2°C (2.2°F) across the available records.
Casper, United States Weather & Climate 2026
Monthly climate averages for Casper, United States. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Feb–Dec 
Wetter season: Jan–Jun At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
5.1/10
Best: June, July, August, September
UV Index
6
High
Temperature 15°C / 2°C
Feels Like 11°C / -2°C
Rainy Days 7
Rainfall 33 mm
Sunshine 10 h
Humidity 57%
Wind Speed 21 km/h
Dew Point 0°C
Snow Days 9 days
Frost Days 20 days
Hottest Month
32°C
July
Avg Low17°C
Rain4days
Coldest Month
-12°C
January
Avg High-2°C
Rain7days
Driest Month
4days
July
Avg High32°C
Avg Low17°C
Windiest Month
23 km/h
June (Gusts 49)
Worst Time to Visit
Consider avoiding January, February, March, November due to very cold temperatures.
Sun Position
Sunrise 05:27
Daylight 15.3h
Sunset 20:47
Live conditions—
Casper on the map · live conditions
Casper, United States
- Continent
- Americas
- Country
- United States
- City
- Casper
- Population
- 60.3K
- Elevation
- 1,560 m
- Coordinates
- 42.87°, -106.31°
Seasonal Breakdown
Spring
Mar–May
Avg High 13°C
Avg Low -1°C
Rain 9 days/mo
Summer
Jun–Aug
Avg High 30°C
Avg Low 15°C
Rain 5 days/mo
3/3 best months
Autumn
Sep–Nov
Avg High 17°C
Avg Low 3°C
Rain 5 days/mo
1/3 best months
Winter
Dec–Feb
Avg High 0°C
Avg Low -11°C
Rain 6 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: -2°C / -12°C . Feb: 0°C / -11°C . Mar: 7°C / -5°C . Apr: 12°C / -2°C . May: 19°C / 5°C . Jun: 28°C / 12°C . Jul: 32°C / 17°C . Aug: 31°C / 15°C . Sep: 26°C / 10°C . Oct: 16°C / 2°C . Nov: 8°C / -3°C . Dec: 1°C / -8°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 27 mm. Feb: 24 mm. Mar: 46 mm. Apr: 59 mm. May: 63 mm. Jun: 31 mm. Jul: 12 mm. Aug: 21 mm. Sep: 25 mm. Oct: 39 mm. Nov: 22 mm. Dec: 22 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 73%. Feb: 70%. Mar: 68%. Apr: 64%. May: 61%. Jun: 44%. Jul: 37%. Aug: 39%. Sep: 44%. Oct: 57%. Nov: 59%. Dec: 65%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 19 km/h . Feb: 22 km/h . Mar: 21 km/h . Apr: 22 km/h . May: 21 km/h . Jun: 23 km/h . Jul: 21 km/h . Aug: 20 km/h . Sep: 21 km/h . Oct: 22 km/h . Nov: 22 km/h . Dec: 22 km/h .
Sunshine
Sunshine
Sunshine: Jan: 7h. Feb: 9h. Mar: 10h. Apr: 11h. May: 12h. Jun: 13h. Jul: 13h. Aug: 12h. Sep: 11h. Oct: 9h. Nov: 8h. Dec: 7h.
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 3. Feb: UV 4. Mar: UV 5. Apr: UV 7. May: UV 7. Jun: UV 8. Jul: UV 8. Aug: UV 7. Sep: UV 6. Oct: UV 5. Nov: UV 3. Dec: UV 3.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 11 days. Feb: 12 days. Mar: 11 days. Apr: 9 days. May: 4 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 5 days. Nov: 7 days. Dec: 9 days.
Climate Trends
Average highs have warmed by 1.2°C (2.2°F) across the available records. Average rainfall has remained broadly steady.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 33°C | Jul · 32°C |
| Coldest month | Jan 2025 · -14°C | Jan · -12°C |
| Wettest month | May 2025 · 72 mm | May · 63 mm |
| Windiest month | Dec 2025 · 28 km/h | Jun · 23 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Poor April
Poor May
Fair June best
Excellent July best
Excellent August best
Excellent September best
Excellent October
Fair November
Poor December
Poor | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | -2°C / -12°C | -7°C / -18°C | 7days (27 mm) Good | 7.3h Good | 73% Muggy | 3.1 Moderate | Poor | View Details |
| February | 0°C / -11°C | -5°C / -17°C | 6days (24 mm) Good | 8.5h Good | 70% Muggy | 3.9 Moderate | Poor | View Details |
| March | 7°C / -5°C | 2°C / -10°C | 8days (46 mm) Wet | 9.8h Good | 68% Muggy | 5.3 High | Poor | View Details |
| April | 12°C / -2°C | 8°C / -6°C | 10days (59 mm) Wet | 10.7h Excellent | 64% Muggy | 6.6 High | Poor | View Details |
| May | 19°C / 5°C | 16°C / 2°C | 10days (63 mm) Wet | 11.8h Excellent | 61% Muggy | 7.4 Very High | Fair | View Details |
| June best | 28°C / 12°C | 25°C / 10°C | 7days (31 mm) Good | 13.4h Excellent | 44% Moderate | 8.2 Very High | Excellent | View Details |
| July best | 32°C / 17°C | 30°C / 15°C | 4days (12 mm) Good | 13.4h Excellent | 37% Comfortable | 8.2 Very High | Excellent | View Details |
| August best | 31°C / 15°C | 28°C / 14°C | 5days (21 mm) Good | 12.3h Excellent | 39% Comfortable | 7.4 Very High | Excellent | View Details |
| September best | 26°C / 10°C | 22°C / 8°C | 5days (25 mm) Good | 10.9h Excellent | 44% Moderate | 6.2 High | Excellent | View Details |
| October | 16°C / 2°C | 11°C / -2°C | 6days (39 mm) Good | 9h Good | 57% Moderate | 4.6 Moderate | Fair | View Details |
| November | 8°C / -3°C | 3°C / -7°C | 5days (22 mm) Good | 7.8h Good | 59% Moderate | 3.1 Moderate | Poor | View Details |
| December | 1°C / -8°C | -4°C / -14°C | 5days (22 mm) Good | 7.1h Good | 65% Muggy | 2.5 Moderate | Poor | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Casper are June, July, August, September, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Casper, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Casper is July, with average daytime highs of 32°C (90°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Casper is January, with average overnight lows of -12°C (10°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Casper is May, averaging 63mm of precipitation across 10 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Casper runs through April, May, with the heaviest rainfall in April. Based on 10-year averages for Casper.
Casper receives approximately 122 sunshine hours per year. The sunniest month is June with around 13 hours. Based on climate data for Casper.
The least favorable months to visit Casper are January, February, March, November, primarily due to very cold temperatures. For the best conditions, consider June, July, August, September instead.
The annual average UV index in Casper is 6, classified as high. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Casper is 57%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Yes, Casper receives snow. Months with snowfall average 9 snow days and 18 cm (7 in) of accumulation, with about 20 frost days during winter.
Average wind speeds in Casper are 21 km/h (13 mph). The windiest month is June with peak winds reaching 23 km/h (14 mph) (gusts up to 49 km/h / 30 mph).
Casper averages 8 clear-sky days per month with overall cloud cover around 45%. The clearest skies occur in September.
The annual average dew point in Casper is 0°C (32°F), which feels dry and comfortable. Outdoor activities are comfortable year-round from a humidity standpoint.
Casper has a Hot-Summer Continental (dry) climate, classified as Dsa under the Köppen system. Continental climates experience extreme temperature ranges — hot summers and cold, snowy winters.
The 'feels like' temperature in Casper ranges from -2°C (28°F) to 11°C (52°F) on average. Wind chill makes winters feel noticeably colder than the actual temperature — layered clothing is recommended.
Yes, June is a great time to visit Casper. It earns a climate score of 8.2/10 with Excellent.
For June in Casper, pack Umbrella, Breathable clothing, Sunscreen (SPF 30+), Sun hat, Sunglasses. With average highs of 28°C (83°F) and 7 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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