Castle Rock weather in May: Castle Rock, Colorado: normal highs, lows, rain and records for May
Castle Rock in May has a normal high of 68°F and a normal low of 42°F, a daily mean of 55°F, rising from 63°F on the 1st to 75°F by the 31st. Measurable precipitation falls on 8 days in a normal May, 1.97 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 20°C and low of 5°C, 50 mm of precipitation and 3 cm of snow in May.
- 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 May?
The normal high is 68°F and the normal low 42°F, for a daily mean of 55.0°F. May is 9.2°F warmer than April and 10.3°F cooler than June. May is the 5th warmest month of the year in Castle Rock and the 5th wettest. Across the month the normal high rises 12°F, from 63°F on May 1 to 75°F on May 31. From one year to the next May's mean temperature typically moves about 2.7°F either way (NOAA's standard deviation), so roughly two Mays in three average between 52°F and 58°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 27%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 63°F | 37°F | 25% | 14% |
| May 8 | 65°F | 39°F | 26% | 15% |
| May 15 | 68°F | 41°F | 26% | 15% |
| May 22 | 71°F | 44°F | 26% | 15% |
| May 31 | 75°F | 46°F | 26% | 15% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 63°F | 37°F | 25% | 14% | 13 h 50 min |
| May 2 | 63°F | 37°F | 25% | 14% | 13 h 50 min |
| May 3 | 63°F | 37°F | 25% | 14% | 13 h 50 min |
| May 4 | 64°F | 38°F | 25% | 14% | 14 h |
| May 5 | 64°F | 38°F | 25% | 14% | 14 h |
| May 6 | 64°F | 38°F | 25% | 14% | 14 h |
| May 7 | 65°F | 39°F | 25% | 15% | 14 h |
| May 8 | 65°F | 39°F | 26% | 15% | 14 h |
| May 9 | 65°F | 39°F | 26% | 15% | 14 h 10 min |
| May 10 | 66°F | 40°F | 26% | 15% | 14 h 10 min |
| May 11 | 66°F | 40°F | 26% | 15% | 14 h 10 min |
| May 12 | 67°F | 40°F | 26% | 15% | 14 h 10 min |
| May 13 | 67°F | 41°F | 26% | 15% | 14 h 10 min |
| May 14 | 68°F | 41°F | 26% | 15% | 14 h 20 min |
| May 15 | 68°F | 41°F | 26% | 15% | 14 h 20 min |
| May 16 | 68°F | 42°F | 26% | 15% | 14 h 20 min |
| May 17 | 69°F | 42°F | 26% | 15% | 14 h 20 min |
| May 18 | 69°F | 42°F | 26% | 15% | 14 h 20 min |
| May 19 | 70°F | 43°F | 26% | 15% | 14 h 30 min |
| May 20 | 70°F | 43°F | 26% | 15% | 14 h 30 min |
| May 21 | 70°F | 43°F | 26% | 15% | 14 h 30 min |
| May 22 | 71°F | 44°F | 26% | 15% | 14 h 30 min |
| May 23 | 71°F | 44°F | 27% | 15% | 14 h 30 min |
| May 24 | 72°F | 44°F | 27% | 15% | 14 h 30 min |
| May 25 | 72°F | 45°F | 27% | 15% | 14 h 40 min |
| May 26 | 73°F | 45°F | 27% | 15% | 14 h 40 min |
| May 27 | 73°F | 45°F | 27% | 15% | 14 h 40 min |
| May 28 | 73°F | 45°F | 27% | 15% | 14 h 40 min |
| May 29 | 74°F | 46°F | 27% | 15% | 14 h 40 min |
| May 30 | 74°F | 46°F | 26% | 15% | 14 h 40 min |
| May 31 | 75°F | 46°F | 26% | 15% | 14 h 40 min |
- Normal high
- 68°FMay average
- Normal low
- 42°FMay average
- Precipitation
- 1.97 inmonth total
- Days with precipitation
- 80.01 inch or more
- Snowfall
- 1.1 inmonth total
- Nights at 32°F or colder
- 4
- Daylight
- 13 h 50 min to 14 h 40 minMay 1 to May 31
- Days at 70°F or more
- 16
- Days at 80°F or more
- 5
- Sunshine
- 76%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 or snow in Castle Rock in May?
On a given May day the chance of 0.01 inch or more is 26% on average, highest around May 25 (27%). In all, 1.97 in falls on 8 days of a normal May.
In a normal May in Castle Rock, 4 nights fall to freezing and snowfall averages 1.1 inches.
Snow falls on 1 day in a normal May, and an inch or more covers the ground on 1 day.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00051401.
What are the records for May in Castle Rock?
The warmest May temperature on this station's record (since 1893) is 94°F, on May 30, 2003; the coldest is 7°F, on May 3, 1907. The wettest May brought 7.48 in (1969); the snowiest, 13.5 inches (1898).
The May mean against the 1991-2020 normal of 55.0°F: 2021 59.3°F (+4.3), 2022 60.8°F (+5.8), 2023 56.4°F (+1.4), 2024 54.3°F (−0.7), 2025 55.3°F (+0.3). 4 of 5 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 59.3°F | +4.3°F | 4.00 in |
| 2022 | 60.8°F | +5.8°F | 2.13 in |
| 2023 | 56.4°F | +1.4°F | 7.05 in |
| 2024 | 54.3°F | −0.7°F | 0.98 in |
| 2025 | 55.3°F | +0.3°F | 3.70 in |
Source: records: ACIS, station USC00051401; recent months: ACIS, station USC00051401. Records and recent months use complete months only.
How does May in Castle Rock compare across Colorado?
Across the 125 places PlainClimate covers in Colorado, May normal highs run from 54°F in Leadville to 80°F in Lamar; Castle Rock's is 68°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.