Chalmers, Indiana climate: Normal weather by month, frost dates and records
Chalmers's normal year runs from 16°F January nights to 83°F July afternoons, with 41.0 inches of precipitation and 20 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.9°C, January lows of −9°C, July highs of 28°C, 1,041 mm of precipitation a year.
- NOAA stationChalmers (5 mi W)
- Station IDUSC00121417
- Location40.67°N 86.95°W
- Elevation720 ft (220 m)
- Population523
On October 22, the normal high in Chalmers is 61°F and the normal low 39°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Chalmers.
- Jan 31° 16°
- Feb 36° 19°
- Mar 47° 28°
- Apr 61° 38°
- May 72° 49°
- Jun 81° 59°
- Jul 83° 62°
- Aug 82° 60°
- Sep 77° 52°
- Oct 65° 41°
- Nov 50° 31°
- Dec 37° 22°
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 Chalmers each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 16°F. The most precipitation falls in June (5.54 in), the least in February (2.06 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 16°F | 23.7°F | 2.54 | 6.6 | 10 | <1 | 29 | 9 h 30 min |
| February | 36°F | 19°F | 27.2°F | 2.06 | 6.2 | 9 | <1 | 26 | 10 h 40 min |
| March | 47°F | 28°F | 37.8°F | 2.78 | 2.5 | 11 | <1 | 21 | 11 h 50 min |
| April | 61°F | 38°F | 49.4°F | 3.93 | 0.4 | 12 | <1 | 9 | 13 h 20 min |
| May | 72°F | 49°F | 60.6°F | 4.26 | 0.0 | 13 | 1 | <1 | 14 h 20 min |
| June | 81°F | 59°F | 70.0°F | 5.54 | 0.0 | 12 | 3 | <1 | 15 h |
| July | 83°F | 62°F | 72.3°F | 4.50 | 0.0 | 10 | 5 | <1 | 14 h 50 min |
| August | 82°F | 60°F | 70.7°F | 4.04 | 0.0 | 9 | 2 | <1 | 13 h 50 min |
| September | 77°F | 52°F | 64.6°F | 3.00 | 0.0 | 9 | 3 | <1 | 12 h 30 min |
| October | 65°F | 41°F | 53.0°F | 3.07 | 0.0 | 10 | <1 | 5 | 11 h 10 min |
| November | 50°F | 31°F | 40.3°F | 2.91 | 0.5 | 10 | <1 | 18 | 10 h |
| December | 37°F | 22°F | 29.4°F | 2.36 | 4.1 | 11 | <1 | 27 | 9 h 20 min |
| Year (annual) | 60°F | 40°F | 49.9°F | 40.99 | 20.3 | 126 | 15 | 134 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.6°C | 65 mm | 17 cm |
| February | 2°C | −7°C | −2.7°C | 52 mm | 16 cm |
| March | 9°C | −2°C | 3.2°C | 71 mm | 6 cm |
| April | 16°C | 3°C | 9.7°C | 100 mm | 1 cm |
| May | 22°C | 10°C | 15.9°C | 108 mm | 0 cm |
| June | 27°C | 15°C | 21.1°C | 141 mm | 0 cm |
| July | 28°C | 17°C | 22.4°C | 114 mm | 0 cm |
| August | 28°C | 15°C | 21.5°C | 103 mm | 0 cm |
| September | 25°C | 11°C | 18.1°C | 76 mm | 0 cm |
| October | 18°C | 5°C | 11.7°C | 78 mm | 0 cm |
| November | 10°C | −1°C | 4.6°C | 74 mm | 1 cm |
| December | 3°C | −6°C | −1.4°C | 60 mm | 10 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00121417; 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 Chalmers?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (9).
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 USC00121417.
When is the last frost in Chalmers?
In Chalmers, the last spring frost (32°F) comes after April 25 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 1 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 251 year in 10 after May 11; 9 in 10 after April 11
- First autumn frost, half of years before
- October 171 year in 10 before October 1; 9 in 10 before October 29
NOAA puts the median frost-free season at 173 days, and the season without a hard freeze (28°F) at 197 days.
A hard freeze (28°F) comes after April 12 in half of springs and before October 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Chalmers in zone 6a in ZIP code 47929, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Chalmers's NOAA station is in zone 5b: the coldest night of a typical year reaches −11°F (16 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Indiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00121417; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 Chalmers?
In a normal year in Chalmers, 15 days a year reach 90°F, 134 nights fall to 32°F or colder and 126 days bring measurable precipitation.
- Days at 90°F or more
- 15a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 134a normal year
- Days that stay below freezing
- 45high of 32°F or less
- Days with 0.01 inch of precipitation
- 126a normal year
- Days with 1 inch of snow or more
- 7a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00121417.
How sunny is Chalmers?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Chalmers, 4.0 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (59%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.8 |
| February | 64% | 2.6 |
| March | 67% | 3.7 |
| April | 70% | 4.8 |
| May | 71% | 5.5 |
| June | 78% | 6.2 |
| July | 81% | 6.2 |
| August | 81% | 5.6 |
| September | 80% | 4.5 |
| October | 72% | 3.1 |
| November | 67% | 2.1 |
| December | 59% | 1.5 |
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 Chalmers need?
A normal year in Chalmers brings 6,218 heating degree days, 16% more than the median U.S. place (5,373), and 757 cooling degree days, 17% fewer 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 3,050 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,280 | 0 |
| February | 1,058 | 0 |
| March | 843 | 2 |
| April | 472 | 4 |
| May | 191 | 55 |
| June | 18 | 169 |
| July | 9 | 237 |
| August | 12 | 189 |
| September | 101 | 88 |
| October | 387 | 13 |
| November | 743 | 0 |
| December | 1,104 | 0 |
| Year (annual) | 6,218 | 757 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00121417. 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.
Has Chalmers been warmer than normal lately?
2025 averaged 51.6°F, 1.7°F above the 1991-2020 normal of 49.9°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.5°F | +2.6°F | 40.87 | 22.9 |
| 2023 | 53.4°F | +3.5°F | 34.93 | 8.9 |
| 2024 | 53.9°F | +4.0°F | 38.30 | 11.2 |
| 2025 | 51.6°F | +1.7°F | 25.06 | 18.9 |
Source: observed years: ACIS, station USC00121417. A year counts only with all twelve months complete.
How does Chalmers's climate compare?
Chalmers is warmer than 13 of the other 98 places with their own NOAA record in Indiana, and wetter than 31. Across the 7,247 U.S. stations with normals, its annual mean of 49.9°F is warmer than 40%.
In the Köppen classification computed from these normals, Chalmers 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 Chalmers share this climate record?
4 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.
- Brookston, IN1,640 people · 6 mi SE
- Wolcott, IN952 people · 8 mi NW
- Reynolds, IN533 people · 7 mi NE
- Norway, IN307 people · 12 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 Chalmers's climate
What is the coldest month in Chalmers?
January, with a normal high of 31°F and a normal low of 16°F. The warmest is July (83°F by day, 62°F at night).
Does it snow in Chalmers?
Yes: 20 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in January (6.6 inches).
What is the rainiest month in Chalmers?
June, with 5.54 in of precipitation in a normal year; the driest is February with 2.06 in.
What plant hardiness zone is Chalmers in?
The USDA's 2023 map puts Chalmers in zone 6a in ZIP code 47929, the nearest ZIP area. By the same method at Chalmers's NOAA station, the coldest night of a typical year reaches −11°F (16 years, 1991-2020): zone 5b.
How late can frost come in Chalmers?
In half of years the last 32°F night comes after April 25; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indiana climateThe statewide normals and every place in the state
- West Lafayette, IN13 miles from this station, 50.4°F a year
- Delphi, IN16 miles from this station, 52.2°F a year
- Lafayette, IN17 miles from this station, 51.3°F a year
- Rensselaer, IN21 miles from this station, 50.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made