Dewey County Weather in May
Average highs run from 64°F on May 1 to 74°F on May 31, and lows from 37°F to 49°F. Normal precipitation for the month is 2.90 in over about 10 wet days.
May day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
May at a glance
- Average high
- 69°F
- Average low
- 43°F
- Precipitation
- 2.90 in
- Snowfall
- 0.6 in
- Record high
- 98°FMay 26, 2006
- Record low
- 15°FMay 3, 2005
- Chance of a freeze
- 86%
- Daylight
- 14 h 18 min to 15 h 23 min
- Cloud cover
- 62%
- Humidity
- 60%
- Dew point
- 42°F
- Wind
- 11.9 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| May 1 | 64°F | 37°F | 87°F 2021 | 22°F 2026 | 30% | 3% |
| May 2 | 64°F | 38°F | 90°F 2015 | 19°F 2013 | 30% | 3% |
| May 3 | 64°F | 38°F | 82°F 2004 | 15°F 2005 | 30% | 2% |
| May 4 | 65°F | 38°F | 84°F 2018 | 21°F 2013 | 31% | 2% |
| May 5 | 65°F | 39°F | 88°F 2000 | 24°F 2026 | 31% | 2% |
| May 6 | 65°F | 39°F | 83°F 2016 | 20°F 2026 | 31% | 2% |
| May 7 | 66°F | 40°F | 91°F 2017 | 26°F 2026 | 31% | 2% |
| May 8 | 66°F | 40°F | 86°F 2004 | 27°F 2020 | 32% | 1% |
| May 9 | 67°F | 41°F | 85°F 2011 | 29°F 2020 | 32% | 1% |
| May 10 | 67°F | 41°F | 89°F 2025 | 25°F 2002 | 32% | 1% |
| May 11 | 67°F | 41°F | 93°F 2025 | 25°F 2020 | 32% | 1% |
| May 12 | 68°F | 42°F | 96°F 2025 | 28°F 2006 | 32% | 1% |
| May 13 | 68°F | 42°F | 93°F 2013 | 30°F 2006 | 32% | 1% |
| May 14 | 69°F | 43°F | 87°F 2001 | 26°F 2004 | 32% | 1% |
| May 15 | 69°F | 43°F | 87°F 2019 | 28°F 2005 | 32% | 1% |
| May 16 | 69°F | 43°F | 87°F 2018 | 27°F 2009 | 32% | 1% |
| May 17 | 70°F | 44°F | 92°F 2012 | 32°F 2002 | 32% | 1% |
| May 18 | 70°F | 44°F | 94°F 2006 | 32°F 2002 | 33% | 1% |
| May 19 | 70°F | 45°F | 87°F 2021 | 31°F 2015 | 33% | 1% |
| May 20 | 71°F | 45°F | 84°F 2005 | 26°F 2003 | 33% | 1% |
| May 21 | 71°F | 46°F | 87°F 2007 | 36°F 2015 | 33% | 0% |
| May 22 | 71°F | 46°F | 87°F 2006 | 32°F 2022 | 33% | 0% |
| May 23 | 72°F | 46°F | 89°F 2006 | 28°F 2002 | 34% | 0% |
| May 24 | 72°F | 47°F | 87°F 2018 | 24°F 2002 | 34% | 0% |
| May 25 | 72°F | 47°F | 91°F 2026 | 35°F 2000 | 34% | 0% |
| May 26 | 73°F | 48°F | 98°F 2006 | 38°F 2007 | 34% | 0% |
| May 27 | 73°F | 48°F | 97°F 2006 | 37°F 2007 | 34% | 0% |
| May 28 | 73°F | 48°F | 90°F 2010 | 36°F 2008 | 34% | 0% |
| May 29 | 74°F | 49°F | 89°F 2002 | 38°F 2012 | 35% | 0% |
| May 30 | 74°F | 49°F | 92°F 2002 | 33°F 2012 | 35% | 0% |
| May 31 | 74°F | 49°F | 93°F 2018 | 32°F 2012 | 35% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- May 1
- sunrise 5:32 AM, sunset 7:50 PM
- May 31
- sunrise 5:00 AM, sunset 8:23 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00398307 (Timber Lake), public domain. Records: NOAA GHCN-Daily, station USW00094052, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.