Keystone, SD weather in July
Expect mild weather with frequent rain in Keystone in July, with highs near 79°F and lows near 51°F. Rain falls on about 12 days. It is one of the warmest months in Keystone.
- Normal high
- 79°F
- Normal low
- 51°F
- Wet days
- 12
- 3.1 in total
- Muggy days
- 1
- dew point 65°F+
How July changes from start to finish
| July 1 | July 31 | |
|---|---|---|
| Normal high | 76°F | 80°F |
| Normal low | 48°F | 52°F |
| Chance of a wet day | 40% | 37% |
| Sunrise / sunset | 5:15 am / 8:39 pm | 5:41 am / 8:18 pm |
| Daylight | 15.4 h | 14.6 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Mountain Time).
A typical July day
- 6 am59°Fdew point 49°F
- 9 am71°Fdew point 49°F
- Noon75°Fdew point 48°F
- 3 pm76°Fdew point 48°F
- 6 pm72°Fdew point 49°F
- 9 pm63°Fdew point 49°F
NOAA hourly normals (local standard time) from Custer Co Airport (15 mi away); average wind 6 mph; clear or few clouds in 58% of daytime hours, mostly cloudy or overcast in 29%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F13 of 31
- Hot dayshigh 90°F or more3 of 31
- Muggy daysdaily mean dew point 65°F or more1 of 31
- Wet daysat least 0.01 in of rain or melted snow12 of 31
- Notable rainat least 0.10 in7 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per July, counted from daily records for each year 1991-2020.
Rain in July
Normal precipitation is 3.1 in; a dry July brings about 2.0 in and a wet one about 3.7 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How July varies from year to year
- Warmest July, 1991-20202006: average high 85°F
- Coolest July1992: average high 69°F
- Wettest July2018: 8.0 in
- Driest July2003: 0.6 in
- Highest reading101°F (July 30, 2006)
- Lowest reading32°F (July 1, 1995)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
July compared with June and August
| June | July | August | |
|---|---|---|---|
| Normal high | 71°F | 79°F | 78°F |
| Normal low | 45°F | 51°F | 49°F |
| Wet days | 13 | 12 | 9 |
| Comfortable days | 16 | 13 | 15 |
| Daylight | 15.4 h | 15.1 h | 13.9 h |
Highs change by +8°F from June and -1°F into August.
Nearby alternatives in July
- Warmer: Rapid City, SD16 mi · high 86°F · 10 wet days
- Drier: Gillette, WY107 mi · high 86°F · 8 wet days
How Keystone ranks in July
- Normal high336th warmest of 378 cities; 4th of 4 in South Dakota
- Wet days321st driest of 378
- Comfortable days32nd most of 340
What to pack for Keystone in July
- Layers – afternoons near 79°F but nights near 51°F
- A rain jacket or umbrella – rain on about 12 days
- Sunglasses and sunscreen – about 15.1 hours of daylight and highs near 79°F
Heating and cooling
July has 81 heating degree days and 73 cooling degree days (base 65°F), 2% of the year's total heating and cooling demand.
Questions
How hot is Keystone in July?
The normal high is 79°F and the normal low is 51°F. From 1991 to 2020 the hottest July reading was 101°F (most recently on July 30, 2006).
Does it rain a lot in Keystone in July?
About 12 days in July have at least 0.01 in of precipitation, and the normal total is 3.1 in. The wettest July in 1991-2020 was in 2018 (8.0 in); the driest was in 2003 (0.6 in).
Is July a good time to visit Keystone?
July ranks 4th of 12 months on our comfort score for Keystone (69 out of 100). It has about 13 comfortable days and about 3 days at 90°F or hotter. The best month is June.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Pactola Dam (USC00396427), 12 mi NNW of the city center, 4,720 ft (385 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Custer Co Airport (USW00094032), 15 mi SW of the city center, 5,545 ft (1,210 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Cloud cover: Ellsworth AFB (USW00024006), 24 mi NE of the city center, 3,215 ft (1,120 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Rapid City Regional Airport (726620-24090), 21 mi ENE of the city center, 3,162 ft (1,173 ft lower than the city). Hourly observations, 1991-2020.