Derby, CO climate
Derby has chilly, snowy winters and warm summers, with very little rain. A typical July afternoon reaches 90°, a January night drops to 18°, and about 49 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Derby feels like
Winter
Spring
Summer
Fall
Derby weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 46° | 18° | 0.4" | 6.4" | 5 | 10 | 22° – 38° |
| February | 48° | 20° | 0.5" | 7.6" | 6 | 9 | 29° – 42° |
| March | 57° | 28° | 1.0" | 8.8" | 7 | 4 | 36° – 49° |
| April | 63° | 34° | 1.8" | 6.2" | 8 | 2 | 42° – 54° |
| May | 72° | 44° | 2.4" | 1.4" | 11 | 0 | 52° – 63° |
| June | 84° | 53° | 1.6" | 0 | 8 | 0 | 64° – 74° |
| July | 90° | 59° | 1.8" | 0 | 9 | 0 | 70° – 77° |
| August | 88° | 57° | 1.5" | 0 | 9 | 0 | 68° – 76° |
| September | 80° | 48° | 1.2" | 0.8" | 6 | 0 | 59° – 69° |
| October | 66° | 36° | 0.9" | 3.9" | 5 | 2 | 43° – 57° |
| November | 54° | 26° | 0.7" | 7.3" | 6 | 5 | 31° – 47° |
| December | 46° | 18° | 0.4" | 6.6" | 5 | 10 | 25° – 36° |
| Year | 66° | 37° | 14.2" | 49.0" | 84 | 43 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Derby
Derby gets 14 inches of rain and melted snow a year. May is the wettest month and January the driest. Rain or snow falls on about 84 days a year. Snow covers the ground about 43 days of the year.
About 156 frost-free days a year
In half of years the last 32° night comes by May 4 and the first one by October 8. That leaves about 156 frost-free days for gardens, shorter than 75% of U.S. towns.
Heating and cooling a home in Derby
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Derby, 88% of that work is heating and 12% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Derby and its neighbors
Derby borders 1 town with climate data. January nights across them vary by 0.5°. Commerce City has both the coldest January nights (17°) and the hottest July afternoons (90°). Derby’s January low is 18° and its July high 90°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Derby compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Derby averaged 1.5° warmer than the 1900s. The biggest change is in March (+3.5°). The shift is larger than in 71% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Derby’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. January swings the most: between 1991 and 2020 its average temperature ranged from 22° to 38°. July is the most reliable, staying within 7°.
Common questions about Derby’s climate
What is the coldest month in Derby?
January, with a typical high of 46° and a low of 18°.
What is the hottest month in Derby?
July, with a typical high of 90° and a low of 59°. About 42 days a year reach 90°.
How much snow does Derby get?
About 49 inches in a normal winter, most of it in March.
When is the first frost in Derby?
In half of years the first 32° night comes by October 8, and the last spring frost by May 4.
What is the rainiest month in Derby?
May, with 2.4 inches of rain and melted snow. The year totals 14 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Derby itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Denver-stapleton, CO (6 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.