Harrison, TN climate
Harrison has mild winters and warm summers, with plenty of rain. A typical July afternoon reaches 90°, a January night drops to 31°, and about 4 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Harrison feels like
Winter
Spring
Summer
Fall
Harrison 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 | 50° | 31° | 5.1" | 1.0" | 11 | 1 | 32° – 48° |
| February | 55° | 34° | 5.4" | 1.2" | 11 | 0 | 34° – 52° |
| March | 63° | 40° | 5.5" | 1.1" | 11 | 0 | 45° – 61° |
| April | 73° | 47° | 5.0" | 0 | 10 | 0 | 55° – 65° |
| May | 80° | 56° | 4.2" | 0 | 11 | 0 | 63° – 73° |
| June | 87° | 65° | 4.4" | 0 | 11 | 0 | 71° – 79° |
| July | 90° | 69° | 4.6" | 0 | 12 | 0 | 76° – 83° |
| August | 89° | 67° | 4.0" | 0 | 9 | 0 | 73° – 84° |
| September | 84° | 61° | 4.5" | 0 | 8 | 0 | 69° – 79° |
| October | 73° | 49° | 3.7" | 0 | 8 | 0 | 58° – 66° |
| November | 62° | 38° | 4.6" | 0 | 9 | 0 | 45° – 55° |
| December | 53° | 33° | 5.7" | 0.3" | 11 | 0 | 34° – 53° |
| Year | 71° | 49° | 56.7" | 3.6" | 123 | 2 |
“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 Harrison
Harrison gets 57 inches of rain and melted snow a year. December is the wettest month and October the driest. Rain or snow falls on about 123 days a year.
About 230 frost-free days a year
In half of years the last 32° night comes by March 24 and the first one by November 9. That leaves about 230 frost-free days for gardens, longer than 86% of U.S. towns.
Heating and cooling a home in Harrison
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Harrison, 61% of that work is heating and 39% is cooling.
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.
Harrison and its neighbors
Harrison borders 1 town with climate data. January nights across them vary by 0.4°. Chattanooga has both the coldest January nights (31°) and the hottest July afternoons (90°). Harrison’s January low is 31° and its July high 90°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Harrison 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 Harrison averaged 0.9° warmer than the 1900s. The biggest change is in December (+2.0°). The shift is smaller than in 76% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Harrison’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 34° to 53°. July is the most reliable, staying within 8°.
Common questions about Harrison’s climate
What is the coldest month in Harrison?
January, with a typical high of 50° and a low of 31°.
What is the hottest month in Harrison?
July, with a typical high of 90° and a low of 69°. About 58 days a year reach 90°.
How much snow does Harrison get?
About 4 inches in a normal winter, most of it in February.
When is the first frost in Harrison?
In half of years the first 32° night comes by November 9, and the last spring frost by March 24.
What is the rainiest month in Harrison?
December, with 5.7 inches of rain and melted snow. The year totals 57 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Harrison itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Chattanooga Lovell Airport, TN (7 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.