Petersburg, Indiana climate: Normal weather by month, frost dates and records
Petersburg's normal year runs from 22°F January nights to 86°F July afternoons, with 47.9 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.2°C, January lows of −6°C, July highs of 30°C, 1,217 mm of precipitation a year.
- NOAA stationPetersburg 61 Bridge
- Station IDUSC00126872
- Location38.47°N 87.27°W
- Elevation472 ft (144 m)
- Population2,269
On October 14, the normal high in Petersburg is 69°F and the normal low 44°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Petersburg.
- Jan 39° 22°
- Feb 44° 24°
- Mar 54° 32°
- Apr 66° 41°
- May 75° 52°
- Jun 83° 61°
- Jul 86° 64°
- Aug 85° 62°
- Sep 80° 54°
- Oct 68° 44°
- Nov 55° 34°
- Dec 43° 26°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Petersburg each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 22°F. The most precipitation falls in April (5.09 in), the least in February (2.93 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 39°F | 22°F | 30.4°F | 3.49 | 9 | <1 | 25 | 9 h 50 min |
| February | 44°F | 24°F | 34.1°F | 2.93 | 8 | <1 | 21 | 10 h 40 min |
| March | 54°F | 32°F | 42.9°F | 3.96 | 10 | <1 | 16 | 11 h 50 min |
| April | 66°F | 41°F | 53.3°F | 5.09 | 11 | <1 | 4 | 13 h 10 min |
| May | 75°F | 52°F | 63.4°F | 4.87 | 11 | 1 | <1 | 14 h 10 min |
| June | 83°F | 61°F | 72.0°F | 4.82 | 9 | 6 | <1 | 14 h 50 min |
| July | 86°F | 64°F | 75.0°F | 4.10 | 8 | 9 | <1 | 14 h 40 min |
| August | 85°F | 62°F | 73.3°F | 3.72 | 6 | 10 | <1 | 13 h 40 min |
| September | 80°F | 54°F | 67.2°F | 3.74 | 7 | 4 | <1 | 12 h 30 min |
| October | 68°F | 44°F | 55.9°F | 3.29 | 7 | <1 | 3 | 11 h 20 min |
| November | 55°F | 34°F | 44.3°F | 4.04 | 9 | <1 | 13 | 10 h 10 min |
| December | 43°F | 26°F | 34.5°F | 3.85 | 10 | <1 | 22 | 9 h 30 min |
| Year (annual) | 65°F | 43°F | 53.9°F | 47.90 | 103 | 28 | 103 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 4°C | −6°C | −0.9°C | 89 mm |
| February | 7°C | −4°C | 1.2°C | 74 mm |
| March | 12°C | 0°C | 6.1°C | 101 mm |
| April | 19°C | 5°C | 11.8°C | 129 mm |
| May | 24°C | 11°C | 17.4°C | 124 mm |
| June | 28°C | 16°C | 22.2°C | 122 mm |
| July | 30°C | 18°C | 23.9°C | 104 mm |
| August | 30°C | 16°C | 22.9°C | 94 mm |
| September | 27°C | 12°C | 19.6°C | 95 mm |
| October | 20°C | 6°C | 13.3°C | 84 mm |
| November | 13°C | 1°C | 6.8°C | 103 mm |
| December | 6°C | −3°C | 1.4°C | 98 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Washington (13 miles away), gets 9 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00126872; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Petersburg?
Normal highs sit between 65°F and 85°F in April, May, June, September and October. Of those, September has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00126872.
When is the last frost in Petersburg?
In Petersburg, the last spring frost (32°F) comes after April 20 in half of years and after May 4 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 8 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 201 year in 10 after May 4; 9 in 10 after April 6
- First autumn frost, half of years before
- October 221 year in 10 before October 8; 9 in 10 before November 2
NOAA puts the median frost-free season at 186 days, and the season without a hard freeze (28°F) at 207 days.
A hard freeze (28°F) comes after April 7 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Petersburg in zone 6b in ZIP code 47567, the nearest ZIP area.
Frost dates for every NOAA station in Indiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00126872; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Petersburg?
In a normal year in Petersburg, 28 days a year reach 90°F, 103 nights fall to 32°F or colder and 103 days bring measurable precipitation.
- Days at 90°F or more
- 28a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 103a normal year
- Days that stay below freezing
- 20high of 32°F or less
- Days with 0.01 inch of precipitation
- 103a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00126872.
How sunny is Petersburg?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Petersburg, 4.1 kWh per square metre a day. August is the sunniest month (82%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 2.0 |
| February | 64% | 2.7 |
| March | 67% | 3.7 |
| April | 72% | 5.0 |
| May | 73% | 5.6 |
| June | 81% | 6.4 |
| July | 82% | 6.3 |
| August | 82% | 5.7 |
| September | 80% | 4.7 |
| October | 75% | 3.4 |
| November | 71% | 2.4 |
| December | 62% | 1.7 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Petersburg need?
A normal year in Petersburg brings 5,064 heating degree days, 6% fewer than the median U.S. place (5,373), and 1,033 cooling degree days, 14% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,629 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,074 | 0 |
| February | 867 | 0 |
| March | 686 | 1 |
| April | 364 | 12 |
| May | 123 | 75 |
| June | 14 | 224 |
| July | 2 | 312 |
| August | 5 | 263 |
| September | 59 | 125 |
| October | 302 | 20 |
| November | 624 | 2 |
| December | 945 | 0 |
| Year (annual) | 5,064 | 1,033 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00126872. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Petersburg's climate compare?
Petersburg is warmer than 72 of the other 98 places with their own NOAA record in Indiana, and wetter than 72. Across the 7,247 U.S. stations with normals, its annual mean of 53.9°F is warmer than 57%.
In the Köppen classification computed from these normals, Petersburg is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Petersburg share this climate record?
5 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Oakland City, IN2,269 people · 10 mi SW
- Winslow, IN761 people · 6 mi SE
- Otwell, IN430 people · 9 mi E
- Glezen, IN243 people · 4 mi SW
- Alford, IN227 people · 2 mi NE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Petersburg's climate
What is the coldest month in Petersburg?
January, with a normal high of 39°F and a normal low of 22°F. The warmest is July (86°F by day, 64°F at night).
Does it snow in Petersburg?
Yes. NOAA publishes no 1991-2020 snowfall normal for Petersburg's NOAA station; the nearest record that keeps one, Washington (13 miles away), records 9 inches of snow in a normal year.
What is the rainiest month in Petersburg?
April, with 5.09 in of precipitation in a normal year; the driest is February with 2.93 in.
What plant hardiness zone is Petersburg in?
The USDA's 2023 map puts Petersburg in zone 6b in ZIP code 47567, the nearest ZIP area.
How late can frost come in Petersburg?
In half of years the last 32°F night comes after April 20; in one year in ten it comes after May 4. Waiting until May 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indiana climateThe statewide normals and every place in the state
- Washington, IN13 miles from this station, 56.3°F a year
- Stendal, IN15 miles from this station, 55.3°F a year
- Princeton, IN19 miles from this station, 55.0°F a year
- Vincennes, IN22 miles from this station, 55.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made