Petersburg, IN climate
Petersburg has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 87°, a January night drops to 23°, and about 9 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decade17° warmer than normal today. The forecast high is 91°, and a typical Oct 1 in Petersburg peaks around 74°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in Petersburg feels like
Winter
Spring
Summer
Fall
Petersburg 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 | 40° | 23° | 3.5" | 2.9" | 8 | 4 | 24° – 42° |
| February | 45° | 26° | 3.0" | 2.0" | 6 | 3 | 24° – 44° |
| March | 55° | 34° | 4.1" | 1.0" | 9 | 1 | 37° – 58° |
| April | 67° | 44° | 5.0" | 0 | 10 | 0 | 49° – 61° |
| May | 76° | 54° | 5.4" | 0 | 11 | 0 | 60° – 73° |
| June | 85° | 63° | 4.7" | 0 | 9 | 0 | 69° – 78° |
| July | 87° | 66° | 4.3" | 0 | 8 | 0 | 72° – 83° |
| August | 86° | 64° | 3.2" | 0 | 7 | 0 | 71° – 80° |
| September | 81° | 56° | 3.8" | 0 | 6 | 0 | 64° – 74° |
| October | 69° | 45° | 3.5" | 0.1" | 6 | 0 | 53° – 62° |
| November | 55° | 35° | 3.9" | 0.1" | 7 | 0 | 38° – 51° |
| December | 44° | 27° | 3.7" | 3.1" | 7 | 2 | 22° – 45° |
| Year | 66° | 45° | 47.9" | 9.2" | 92 | 10 |
“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 Petersburg
Petersburg gets 48 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 92 days a year. Snow covers the ground about 10 days of the year.
About 186 frost-free days a year
In half of years the last 32° night comes by April 20 and the first one by October 22. That leaves about 186 frost-free days for gardens, longer than 59% of U.S. towns.
Heating and cooling a home in Petersburg
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Petersburg, 83% of that work is heating and 17% 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 Petersburg 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 Petersburg averaged 1.0° warmer than the 1900s. The biggest change is in December (+1.9°). The shift is smaller than in 68% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Petersburg’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 22° to 45°. June is the most reliable, staying within 9°.
Common questions about Petersburg’s climate
What is the coldest month in Petersburg?
January, with a typical high of 40° and a low of 23°.
What is the hottest month in Petersburg?
July, with a typical high of 87° and a low of 66°. About 28 days a year reach 90°.
How much snow does Petersburg get?
About 9 inches in a normal winter, most of it in December.
When is the first frost in Petersburg?
In half of years the first 32° night comes by October 22, and the last spring frost by April 20.
What is the rainiest month in Petersburg?
May, with 5.4 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Petersburg itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Washington 1 W, IN (12 mi, snow) and Petersburg 61 Brg, IN (2 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.