Jamestown, Indiana climate: Normal weather by month, frost dates and records
Jamestown's normal year runs from 18°F January nights to 83°F July afternoons, with 43.3 inches of precipitation and 14 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.7°C, January lows of −8°C, July highs of 28°C, 1,099 mm of precipitation a year.
- NOAA stationJamestown (2 mi E)
- Station IDUSC00124356
- Location39.92°N 86.60°W
- Elevation962 ft (293 m)
- Population964
On October 23, the normal high in Jamestown is 62°F and the normal low 41°F, and the chance of measurable rain or snow is 25%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Jamestown.
- Jan 34° 18°
- Feb 38° 21°
- Mar 49° 30°
- Apr 62° 40°
- May 72° 51°
- Jun 80° 60°
- Jul 83° 63°
- Aug 82° 61°
- Sep 77° 54°
- Oct 65° 43°
- Nov 51° 32°
- Dec 39° 23°
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 Jamestown each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 18°F. The most precipitation falls in June (5.16 in), the least in February (2.38 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 34°F | 18°F | 25.7°F | 2.59 | 5.0 | 9 | <1 | 27 | 9 h 40 min |
| February | 38°F | 21°F | 29.4°F | 2.38 | 2.0 | 7 | <1 | 24 | 10 h 40 min |
| March | 49°F | 30°F | 39.5°F | 3.12 | 2.2 | 10 | <1 | 20 | 11 h 50 min |
| April | 62°F | 40°F | 50.8°F | 4.49 | 0.2 | 11 | <1 | 7 | 13 h 10 min |
| May | 72°F | 51°F | 61.7°F | 4.90 | 0.0 | 12 | <1 | <1 | 14 h 20 min |
| June | 80°F | 60°F | 70.3°F | 5.16 | 0.0 | 10 | 2 | <1 | 15 h |
| July | 83°F | 63°F | 72.9°F | 4.46 | 0.0 | 9 | 4 | <1 | 14 h 50 min |
| August | 82°F | 61°F | 71.6°F | 3.25 | 0.0 | 8 | 3 | <1 | 13 h 50 min |
| September | 77°F | 54°F | 65.6°F | 3.33 | 0.0 | 7 | 2 | <1 | 12 h 30 min |
| October | 65°F | 43°F | 54.0°F | 3.53 | 0.0 | 7 | <1 | 5 | 11 h 10 min |
| November | 51°F | 32°F | 41.4°F | 3.33 | 0.8 | 9 | <1 | 17 | 10 h |
| December | 39°F | 23°F | 30.9°F | 2.72 | 3.8 | 9 | <1 | 25 | 9 h 20 min |
| Year (annual) | 61°F | 41°F | 51.2°F | 43.26 | 14.0 | 105 | 11 | 127 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −8°C | −3.5°C | 66 mm | 13 cm |
| February | 3°C | −6°C | −1.4°C | 60 mm | 5 cm |
| March | 10°C | −1°C | 4.2°C | 79 mm | 6 cm |
| April | 16°C | 4°C | 10.4°C | 114 mm | 1 cm |
| May | 22°C | 11°C | 16.5°C | 124 mm | 0 cm |
| June | 27°C | 16°C | 21.3°C | 131 mm | 0 cm |
| July | 28°C | 17°C | 22.7°C | 113 mm | 0 cm |
| August | 28°C | 16°C | 22.0°C | 83 mm | 0 cm |
| September | 25°C | 12°C | 18.7°C | 85 mm | 0 cm |
| October | 18°C | 6°C | 12.2°C | 90 mm | 0 cm |
| November | 10°C | 0°C | 5.2°C | 85 mm | 2 cm |
| December | 4°C | −5°C | −0.6°C | 69 mm | 10 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00124356; 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 Jamestown?
Normal highs sit between 65°F and 85°F in May, June, July, August, 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 USC00124356.
When is the last frost in Jamestown?
In Jamestown, the last spring frost (32°F) comes after April 23 in half of years and after May 9 in one year in ten; the first autumn frost comes before October 19 in half of years and before October 4 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 231 year in 10 after May 9; 9 in 10 after April 8
- First autumn frost, half of years before
- October 191 year in 10 before October 4; 9 in 10 before November 1
NOAA puts the median frost-free season at 178 days, and the season without a hard freeze (28°F) at 204 days.
A hard freeze (28°F) comes after April 9 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Jamestown in zone 6a in ZIP code 46147, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Jamestown's NOAA station is in zone 6a: the coldest night of a typical year reaches −6°F (20 complete years).
Frost dates for every NOAA station in Indiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00124356; 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 Jamestown?
In a normal year in Jamestown, 11 days a year reach 90°F, 127 nights fall to 32°F or colder and 105 days bring measurable precipitation.
- Days at 90°F or more
- 11a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 127a normal year
- Days that stay below freezing
- 35high of 32°F or less
- Days with 0.01 inch of precipitation
- 105a normal year
- Days with 1 inch of snow or more
- 5a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00124356.
How sunny is Jamestown?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Jamestown, 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 | 63% | 2.6 |
| March | 66% | 3.7 |
| April | 71% | 4.8 |
| May | 72% | 5.5 |
| June | 79% | 6.3 |
| July | 80% | 6.1 |
| August | 81% | 5.5 |
| September | 80% | 4.6 |
| October | 73% | 3.2 |
| November | 69% | 2.2 |
| December | 59% | 1.6 |
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 Jamestown need?
A normal year in Jamestown brings 5,850 heating degree days, 9% more than the median U.S. place (5,373), and 840 cooling degree days, 7% 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 3,243 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,217 | 0 |
| February | 997 | 0 |
| March | 794 | 2 |
| April | 433 | 7 |
| May | 167 | 65 |
| June | 26 | 185 |
| July | 4 | 250 |
| August | 8 | 212 |
| September | 84 | 102 |
| October | 356 | 16 |
| November | 709 | 1 |
| December | 1,057 | 0 |
| Year (annual) | 5,850 | 840 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00124356. 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 Jamestown been warmer than normal lately?
2023 averaged 53.2°F, 2.0°F above the 1991-2020 normal of 51.2°F. 3 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.6°F | +1.4°F | – | – |
| 2022 | 51.5°F | +0.3°F | – | – |
| 2023 | 53.2°F | +2.0°F | – | – |
Source: observed years: ACIS, station USC00124356. A year counts only with all twelve months complete.
How does Jamestown's climate compare?
Jamestown is warmer than 41 of the other 98 places with their own NOAA record in Indiana, and wetter than 47. Across the 7,247 U.S. stations with normals, its annual mean of 51.2°F is warmer than 46%.
In the Köppen classification computed from these normals, Jamestown 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 Jamestown 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.
- Pittsboro, IN4,288 people · 8 mi SE
- Advance, IN512 people · 5 mi N
- Lizton, IN507 people · 4 mi SE
- North Salem, IN474 people · 5 mi SW
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 Jamestown's climate
What is the coldest month in Jamestown?
January, with a normal high of 34°F and a normal low of 18°F. The warmest is July (83°F by day, 63°F at night).
Does it snow in Jamestown?
Yes: 14 inches in a normal year, falling on 10 days with 0.1 inch or more, the most in January (5.0 inches).
What is the rainiest month in Jamestown?
June, with 5.16 in of precipitation in a normal year; the driest is February with 2.38 in.
What plant hardiness zone is Jamestown in?
The USDA's 2023 map puts Jamestown in zone 6a in ZIP code 46147, the nearest ZIP area. By the same method at Jamestown's NOAA station, the coldest night of a typical year reaches −6°F (20 years, 1991-2020): zone 6a.
How late can frost come in Jamestown?
In half of years the last 32°F night comes after April 23; in one year in ten it comes after May 9. Waiting until May 9 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indiana climateThe statewide normals and every place in the state
- Crawfordsville, IN12 miles from this station, 50.4°F a year
- Whitestown, IN14 miles from this station, 51.9°F a year
- Indianapolis, IN22 miles from this station, 53.6°F a year
- Greencastle, IN24 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