Portland, Indiana climate: Normal weather by month, frost dates and records
Portland's normal year runs from 17°F January nights to 84°F July afternoons, with 39.9 inches of precipitation and 19 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.2°C, January lows of −8°C, July highs of 29°C, 1,014 mm of precipitation a year.
- NOAA stationPortland (1 mi SW)
- Station IDUSC00127069
- Location40.42°N 84.99°W
- Elevation910 ft (277 m)
- From the center1 miles
- Population6,233
On October 23, the normal high in Portland is 61°F and the normal low 39°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Portland.
- Jan 34° 17°
- Feb 38° 19°
- Mar 48° 28°
- Apr 62° 38°
- May 72° 49°
- Jun 80° 59°
- Jul 84° 62°
- Aug 82° 60°
- Sep 77° 52°
- Oct 64° 41°
- Nov 51° 31°
- 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 Portland each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 17°F. The most precipitation falls in June (4.55 in), the least in December (2.39 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 34°F | 17°F | 25.4°F | 2.82 | 6.4 | 10 | <1 | 28 | 9 h 30 min |
| February | 38°F | 19°F | 28.3°F | 2.71 | 5.4 | 8 | <1 | 25 | 10 h 40 min |
| March | 48°F | 28°F | 37.9°F | 2.80 | 3.1 | 9 | <1 | 21 | 11 h 50 min |
| April | 62°F | 38°F | 49.7°F | 3.62 | 0.3 | 11 | <1 | 9 | 13 h 10 min |
| May | 72°F | 49°F | 60.4°F | 4.31 | 0.0 | 12 | <1 | 1 | 14 h 20 min |
| June | 80°F | 59°F | 69.6°F | 4.55 | 0.0 | 10 | 3 | <1 | 15 h |
| July | 84°F | 62°F | 72.8°F | 4.07 | 0.0 | 8 | 5 | <1 | 14 h 50 min |
| August | 82°F | 60°F | 70.8°F | 3.83 | 0.0 | 7 | 3 | <1 | 13 h 50 min |
| September | 77°F | 52°F | 64.4°F | 2.97 | 0.0 | 7 | 2 | <1 | 12 h 30 min |
| October | 64°F | 41°F | 52.7°F | 2.85 | 0.1 | 8 | <1 | 5 | 11 h 10 min |
| November | 51°F | 31°F | 40.8°F | 3.01 | 0.6 | 8 | <1 | 18 | 10 h |
| December | 39°F | 23°F | 30.9°F | 2.39 | 3.5 | 9 | <1 | 26 | 9 h 20 min |
| Year (annual) | 61°F | 40°F | 50.3°F | 39.93 | 19.4 | 109 | 13 | 132 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −8°C | −3.7°C | 72 mm | 16 cm |
| February | 3°C | −7°C | −2.1°C | 69 mm | 14 cm |
| March | 9°C | −2°C | 3.3°C | 71 mm | 8 cm |
| April | 16°C | 3°C | 9.8°C | 92 mm | 1 cm |
| May | 22°C | 10°C | 15.8°C | 109 mm | 0 cm |
| June | 27°C | 15°C | 20.9°C | 116 mm | 0 cm |
| July | 29°C | 17°C | 22.7°C | 103 mm | 0 cm |
| August | 28°C | 15°C | 21.6°C | 97 mm | 0 cm |
| September | 25°C | 11°C | 18.0°C | 75 mm | 0 cm |
| October | 18°C | 5°C | 11.5°C | 72 mm | 0 cm |
| November | 10°C | 0°C | 4.9°C | 76 mm | 2 cm |
| December | 4°C | −5°C | −0.6°C | 61 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00127069; 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 Portland?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, August 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 USC00127069.
When is the last frost in Portland?
In Portland, the last spring frost (32°F) comes after April 28 in half of years and after May 14 in one year in ten; the first autumn frost comes before October 15 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 281 year in 10 after May 14; 9 in 10 after April 13
- First autumn frost, half of years before
- October 151 year in 10 before October 1; 9 in 10 before October 30
NOAA puts the median frost-free season at 171 days, and the season without a hard freeze (28°F) at 194 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Portland in zone 6a in ZIP code 47371, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Portland's NOAA station is in zone 6a: the coldest night of a typical year reaches −8°F (18 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 USC00127069; 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 Portland?
In a normal year in Portland, 13 days a year reach 90°F, 132 nights fall to 32°F or colder and 109 days bring measurable precipitation.
- Days at 90°F or more
- 13a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 132a normal year
- Days that stay below freezing
- 38high of 32°F or less
- Days with 0.01 inch of precipitation
- 109a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1964) is 104°F, on June 29, 2012; the lowest is −29°F, on January 20, 1985.
The wettest calendar year on that record is 1990, with 54.65 in; the snowiest season is 1966–67, with 49.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00127069; records: ACIS (NOAA Regional Climate Centers), station USC00127069. Records use complete months only; a month missing more than three days is left out.
How sunny is Portland?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Portland, 3.9 kWh per square metre a day. August is the sunniest month (81%) and December the cloudiest (57%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 58% | 1.7 |
| February | 63% | 2.6 |
| March | 65% | 3.6 |
| April | 69% | 4.8 |
| May | 72% | 5.5 |
| June | 77% | 6.2 |
| July | 80% | 6.2 |
| August | 81% | 5.6 |
| September | 78% | 4.5 |
| October | 70% | 3.0 |
| November | 67% | 2.1 |
| December | 57% | 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 Portland need?
A normal year in Portland brings 6,090 heating degree days, 13% more than the median U.S. place (5,373), and 771 cooling degree days, 15% 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 3,064 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,227 | 0 |
| February | 1,028 | 0 |
| March | 839 | 1 |
| April | 466 | 7 |
| May | 194 | 53 |
| June | 34 | 170 |
| July | 5 | 247 |
| August | 12 | 191 |
| September | 105 | 87 |
| October | 396 | 15 |
| November | 727 | 1 |
| December | 1,057 | 0 |
| Year (annual) | 6,090 | 771 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00127069. 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 Portland been warmer than normal lately?
2025 averaged 50.8°F, 0.5°F above the 1991-2020 normal of 50.3°F.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2025 | 50.8°F | +0.5°F | 35.28 | 19.1 |
Over 30 complete years from 1979 to 2025, the station's annual mean temperature rose at a fitted 6.3°F per century (+0.35°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00127069; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Portland's climate compare?
Portland is warmer than 25 of the other 98 places with their own NOAA record in Indiana, and wetter than 17. Across the 7,247 U.S. stations with normals, its annual mean of 50.3°F is warmer than 42%.
In the Köppen classification computed from these normals, Portland 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 Portland 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.
- St. Henry, OH2,608 people · 19 mi E
- Fort Recovery, OH1,474 people · 11 mi E
- Burkettsville, OH267 people · 19 mi E
- Bryant, IN237 people · 8 mi N
- Salamonia, IN147 people · 7 mi E
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 Portland's climate
What is the coldest month in Portland?
January, with a normal high of 34°F and a normal low of 17°F. The warmest is July (84°F by day, 62°F at night).
Does it snow in Portland?
Yes: 19 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in January (6.4 inches).
What is the rainiest month in Portland?
June, with 4.55 in of precipitation in a normal year; the driest is December with 2.39 in.
What plant hardiness zone is Portland in?
The USDA's 2023 map puts Portland in zone 6a in ZIP code 47371, the nearest ZIP area. By the same method at Portland's NOAA station, the coldest night of a typical year reaches −8°F (18 years, 1991-2020): zone 6a.
How late can frost come in Portland?
In half of years the last 32°F night comes after April 28; in one year in ten it comes after May 14. Waiting until May 14 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indiana climateThe statewide normals and every place in the state
- Farmland, IN14 miles from this station, 51.2°F a year
- Hartford City, IN16 miles from this station, 51.3°F a year
- Winchester, IN17 miles from this station, 50.8°F a year
- Berne, IN17 miles from this station, 50.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made