Green Castle, MO climate
Green Castle has chilly winters and warm summers. A typical July afternoon reaches 86°, a January night drops to 16°, and about 19 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Green Castle feels like
Winter
Spring
Summer
Fall
Green Castle 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 | 30-yr range |
|---|---|---|---|---|---|---|
| January | 34° | 16° | 1.3" | 6.0" | 6 | 18° – 36° |
| February | 39° | 20° | 1.6" | 4.6" | 7 | 18° – 41° |
| March | 51° | 30° | 2.5" | 2.2" | 8 | 33° – 54° |
| April | 63° | 41° | 3.9" | 0.8" | 11 | 44° – 58° |
| May | 72° | 52° | 5.7" | 0 | 12 | 57° – 71° |
| June | 82° | 61° | 5.2" | 0 | 11 | 68° – 75° |
| July | 86° | 65° | 4.5" | 0 | 9 | 70° – 83° |
| August | 84° | 63° | 4.3" | 0 | 9 | 68° – 79° |
| September | 77° | 55° | 4.1" | 0 | 8 | 60° – 72° |
| October | 65° | 43° | 3.1" | 0.1" | 9 | 47° – 59° |
| November | 51° | 31° | 2.3" | 1.3" | 8 | 32° – 50° |
| December | 38° | 21° | 1.7" | 4.0" | 7 | 15° – 38° |
| Year | 62° | 42° | 40.1" | 19.0" | 104 |
“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 Green Castle
Green Castle gets 40 inches of rain and melted snow a year. May is the wettest month and January the driest. Rain or snow falls on about 104 days a year.
About 169 frost-free days a year
In half of years the last 32° night comes by April 26 and the first one by October 14. That leaves about 169 frost-free days for gardens, shorter than 62% of U.S. towns.
Heating and cooling a home in Green Castle
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Green Castle, 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.
How Green Castle 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 Green Castle averaged 0.6° warmer than the 1900s. The biggest change is in December (+2.0°). The shift is smaller than in 94% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Green Castle’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 15° to 38°. June is the most reliable, staying within 8°.
Common questions about Green Castle’s climate
What is the coldest month in Green Castle?
January, with a typical high of 34° and a low of 16°.
What is the hottest month in Green Castle?
July, with a typical high of 86° and a low of 65°. About 25 days a year reach 90°.
How much snow does Green Castle get?
About 19 inches in a normal winter, most of it in January.
When is the first frost in Green Castle?
In half of years the first 32° night comes by October 14, and the last spring frost by April 26.
What is the rainiest month in Green Castle?
May, with 5.7 inches of rain and melted snow. The year totals 40 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Green Castle itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Kirksville, MO (16 mi, snow) and Green City 5n, MO (7 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.