Castle Rock weather in August: Castle Rock, Colorado: normal highs, lows, rain and records for August
Castle Rock in August has a normal high of 84°F and a normal low of 55°F, a daily mean of 69°F, falling from 85°F on the 1st to 82°F by the 31st. Measurable precipitation falls on 10 days in a normal August, 2.52 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 29°C and low of 13°C, 64 mm of precipitation in August.
- NOAA stationCastle Rock
- Station IDUSC00051401
- Location39.41°N 104.91°W
- Elevation6,185 ft (1,885 m)
- Population83,213
- Jan 46° 18°
- Feb 47° 20°
- Mar 54° 27°
- Apr 59° 33°
- May 68° 42°
- Jun 80° 51°
- Jul 86° 56°
- Aug 84° 55°
- Sep 77° 47°
- Oct 65° 35°
- Nov 54° 26°
- Dec 46° 18°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Castle Rock in August?
The normal high is 84°F and the normal low 55°F, for a daily mean of 69.1°F. August is 2.0°F cooler than July and 7.4°F warmer than September. August is the 2nd warmest month of the year in Castle Rock and the wettest. Across the month the normal high falls 3°F, from 85°F on August 1 to 82°F on August 31. From one year to the next August's mean temperature typically moves about 2.2°F either way (NOAA's standard deviation), so roughly two Augusts in three average between 67°F and 71°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 32%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| August 1 | 85°F | 57°F | 32% | 18% |
| August 8 | 85°F | 56°F | 32% | 18% |
| August 15 | 84°F | 55°F | 31% | 16% |
| August 22 | 83°F | 54°F | 30% | 15% |
| August 31 | 82°F | 52°F | 26% | 13% |
Every day of August: normal high, low and chance of precipitation (warmest afternoon August 1, coldest night August 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| August 1 | 85°F | 57°F | 32% | 18% | 14 h 20 min |
| August 2 | 85°F | 57°F | 32% | 18% | 14 h 10 min |
| August 3 | 85°F | 57°F | 32% | 18% | 14 h 10 min |
| August 4 | 85°F | 56°F | 32% | 18% | 14 h 10 min |
| August 5 | 85°F | 56°F | 32% | 18% | 14 h 10 min |
| August 6 | 85°F | 56°F | 32% | 18% | 14 h 10 min |
| August 7 | 85°F | 56°F | 32% | 18% | 14 h |
| August 8 | 85°F | 56°F | 32% | 18% | 14 h |
| August 9 | 85°F | 56°F | 32% | 18% | 14 h |
| August 10 | 84°F | 56°F | 32% | 17% | 14 h |
| August 11 | 84°F | 56°F | 32% | 17% | 13 h 50 min |
| August 12 | 84°F | 56°F | 32% | 17% | 13 h 50 min |
| August 13 | 84°F | 55°F | 32% | 17% | 13 h 50 min |
| August 14 | 84°F | 55°F | 32% | 17% | 13 h 50 min |
| August 15 | 84°F | 55°F | 31% | 16% | 13 h 50 min |
| August 16 | 84°F | 55°F | 31% | 16% | 13 h 40 min |
| August 17 | 84°F | 55°F | 31% | 16% | 13 h 40 min |
| August 18 | 84°F | 55°F | 31% | 16% | 13 h 40 min |
| August 19 | 83°F | 54°F | 31% | 16% | 13 h 40 min |
| August 20 | 83°F | 54°F | 30% | 16% | 13 h 30 min |
| August 21 | 83°F | 54°F | 30% | 16% | 13 h 30 min |
| August 22 | 83°F | 54°F | 30% | 15% | 13 h 30 min |
| August 23 | 83°F | 54°F | 30% | 15% | 13 h 30 min |
| August 24 | 83°F | 54°F | 29% | 15% | 13 h 30 min |
| August 25 | 83°F | 53°F | 29% | 15% | 13 h 20 min |
| August 26 | 82°F | 53°F | 28% | 14% | 13 h 20 min |
| August 27 | 82°F | 53°F | 28% | 14% | 13 h 20 min |
| August 28 | 82°F | 53°F | 28% | 14% | 13 h 20 min |
| August 29 | 82°F | 53°F | 27% | 14% | 13 h 10 min |
| August 30 | 82°F | 52°F | 27% | 13% | 13 h 10 min |
| August 31 | 82°F | 52°F | 26% | 13% | 13 h 10 min |
- Normal high
- 84°FAugust average
- Normal low
- 55°FAugust average
- Precipitation
- 2.52 inmonth total
- Days with precipitation
- 100.01 inch or more
- Days at 90°F or more
- 6
- Daylight
- 14 h 20 min to 13 h 10 minAugust 1 to August 31
- Days at 70°F or more
- 30
- Days at 80°F or more
- 24
- Sunshine
- 84%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00051401; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Castle Rock in August?
On a given August day the chance of 0.01 inch or more is 31% on average, highest around August 6 (32%). In all, 2.52 in falls on 10 days of a normal August, 1 of them with an inch or more.
In a normal August in Castle Rock, 6 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00051401.
What are the records for August in Castle Rock?
The warmest August temperature on this station's record (since 1893) is 99°F, on August 29, 1904; the coldest is 34°F, on August 26, 1910. The wettest August brought 8.10 in (1897).
The August mean against the 1991-2020 normal of 69.1°F: 2021 76.2°F (+7.1), 2023 70.0°F (+0.9), 2024 71.9°F (+2.8), 2025 70.7°F (+1.6). 4 of 4 ran warmer than normal.
| August | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 76.2°F | +7.1°F | 1.17 in |
| 2023 | 70.0°F | +0.9°F | 4.09 in |
| 2024 | 71.9°F | +2.8°F | 2.35 in |
| 2025 | 70.7°F | +1.6°F | 1.51 in |
Source: records: ACIS, station USC00051401; recent months: ACIS, station USC00051401. Records and recent months use complete months only.
How does August in Castle Rock compare across Colorado?
Across the 125 places PlainClimate covers in Colorado, August normal highs run from 68°F in Leadville to 93°F in Lamar; Castle Rock's is 84°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.