Delphi, Indiana climate: Normal weather by month, frost dates and records
Delphi's normal year runs from 19°F January nights to 85°F July afternoons, with 39.0 inches of precipitation and 17 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.2°C, January lows of −7°C, July highs of 29°C, 992 mm of precipitation a year.
- NOAA stationDelphi (2 mi N)
- Station IDUSC00122149
- Location40.62°N 86.67°W
- Elevation556 ft (170 m)
- Population3,018
On October 22, the normal high in Delphi is 63°F and the normal low 42°F, and the chance of measurable rain or snow is 24%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Delphi.
- Jan 34° 19°
- Feb 39° 22°
- Mar 51° 31°
- Apr 64° 41°
- May 74° 52°
- Jun 82° 60°
- Jul 85° 63°
- Aug 83° 61°
- Sep 78° 54°
- Oct 66° 44°
- Nov 51° 34°
- Dec 39° 25°
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 Delphi each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 19°F. The most precipitation falls in June (4.64 in), the least in February (1.79 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 34°F | 19°F | 26.8°F | 2.65 | 5.8 | 9 | <1 | 27 | 9 h 30 min |
| February | 39°F | 22°F | 30.5°F | 1.79 | 3.5 | 7 | <1 | 23 | 10 h 40 min |
| March | 51°F | 31°F | 41.1°F | 2.84 | 2.5 | 8 | <1 | 18 | 11 h 50 min |
| April | 64°F | 41°F | 52.5°F | 3.80 | 0.2 | 10 | <1 | 6 | 13 h 10 min |
| May | 74°F | 52°F | 62.9°F | 4.09 | 0.0 | 11 | 1 | <1 | 14 h 20 min |
| June | 82°F | 60°F | 71.1°F | 4.64 | 0.0 | 9 | 5 | <1 | 15 h |
| July | 85°F | 63°F | 73.9°F | 4.61 | 0.0 | 9 | 6 | <1 | 14 h 50 min |
| August | 83°F | 61°F | 72.3°F | 3.46 | 0.0 | 7 | 5 | <1 | 13 h 50 min |
| September | 78°F | 54°F | 65.9°F | 2.93 | 0.0 | 6 | 3 | <1 | 12 h 30 min |
| October | 66°F | 44°F | 54.8°F | 3.00 | 0.0 | 7 | <1 | 4 | 11 h 10 min |
| November | 51°F | 34°F | 42.4°F | 2.94 | 0.5 | 8 | <1 | 14 | 10 h |
| December | 39°F | 25°F | 31.8°F | 2.29 | 4.7 | 8 | <1 | 25 | 9 h 20 min |
| Year (annual) | 62°F | 42°F | 52.2°F | 39.04 | 17.2 | 98 | 20 | 117 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −7°C | −2.9°C | 67 mm | 15 cm |
| February | 4°C | −5°C | −0.8°C | 45 mm | 9 cm |
| March | 10°C | 0°C | 5.1°C | 72 mm | 6 cm |
| April | 18°C | 5°C | 11.4°C | 97 mm | 1 cm |
| May | 24°C | 11°C | 17.2°C | 104 mm | 0 cm |
| June | 28°C | 16°C | 21.7°C | 118 mm | 0 cm |
| July | 29°C | 17°C | 23.3°C | 117 mm | 0 cm |
| August | 29°C | 16°C | 22.4°C | 88 mm | 0 cm |
| September | 26°C | 12°C | 18.8°C | 74 mm | 0 cm |
| October | 19°C | 6°C | 12.7°C | 76 mm | 0 cm |
| November | 11°C | 1°C | 5.8°C | 75 mm | 1 cm |
| December | 4°C | −4°C | −0.1°C | 58 mm | 12 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00122149; 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 Delphi?
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 (6).
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 USC00122149.
When is the last frost in Delphi?
In Delphi, the last spring frost (32°F) comes after April 22 in half of years and after May 6 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 3 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 221 year in 10 after May 6; 9 in 10 after April 7
- First autumn frost, half of years before
- October 171 year in 10 before October 3; 9 in 10 before November 1
NOAA puts the median frost-free season at 179 days, and the season without a hard freeze (28°F) at 203 days.
A hard freeze (28°F) comes after April 8 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Delphi in zone 6a in ZIP code 46923, 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 USC00122149; 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 Delphi?
In a normal year in Delphi, 20 days a year reach 90°F, 117 nights fall to 32°F or colder and 98 days bring measurable precipitation.
- Days at 90°F or more
- 20a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 117a normal year
- Days that stay below freezing
- 32high of 32°F or less
- Days with 0.01 inch of precipitation
- 98a normal year
- Days with 1 inch of snow or more
- 7a normal year
The highest temperature in this station's record (since 1893) is 112°F, on July 24, 1934; the lowest is −25°F, on January 18, 1930.
The wettest calendar year on that record is 1990, with 51.06 in; the snowiest season is 1977–78, with 44.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00122149; records: ACIS (NOAA Regional Climate Centers), station USC00122149. Records use complete months only; a month missing more than three days is left out.
How sunny is Delphi?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Delphi, 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 Delphi need?
A normal year in Delphi brings 5,570 heating degree days, 4% more than the median U.S. place (5,373), and 928 cooling degree days, 2% 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 3,403 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,184 | 0 |
| February | 964 | 0 |
| March | 744 | 1 |
| April | 390 | 14 |
| May | 140 | 77 |
| June | 21 | 205 |
| July | 2 | 278 |
| August | 7 | 233 |
| September | 76 | 103 |
| October | 336 | 18 |
| November | 680 | 1 |
| December | 1,027 | 0 |
| Year (annual) | 5,570 | 928 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00122149. 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 Delphi's climate compare?
Delphi is warmer than 58 of the other 98 places with their own NOAA record in Indiana, and wetter than 8. Across the 7,247 U.S. stations with normals, its annual mean of 52.2°F is warmer than 50%.
In the Köppen classification computed from these normals, Delphi 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 Delphi share this climate record?
12 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.
- Monticello, IN5,519 people · 10 mi NW
- Flora, IN2,117 people · 9 mi SE
- Camden, IN609 people · 7 mi E
- Burnettsville, IN391 people · 11 mi N
- Idaville, IN391 people · 10 mi N
- Pittsburg, IN208 people · 2 mi SW
- Rockfield, IN192 people · 5 mi E
- Colburn, IN144 people · 7 mi S
- Yeoman, IN120 people · 5 mi NW
- Buck Creek, IN75 people · 10 mi SW
- Bringhurst, IN70 people · 10 mi SE
- Americus, IN56 people · 8 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 Delphi's climate
What is the coldest month in Delphi?
January, with a normal high of 34°F and a normal low of 19°F. The warmest is July (85°F by day, 63°F at night).
Does it snow in Delphi?
Yes: 17 inches in a normal year, falling on 12 days with 0.1 inch or more, the most in January (5.8 inches).
What is the rainiest month in Delphi?
June, with 4.64 in of precipitation in a normal year; the driest is February with 1.79 in.
What plant hardiness zone is Delphi in?
The USDA's 2023 map puts Delphi in zone 6a in ZIP code 46923, the nearest ZIP area.
How late can frost come in Delphi?
In half of years the last 32°F night comes after April 22; in one year in ten it comes after May 6. Waiting until May 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Indiana climateThe statewide normals and every place in the state
- Chalmers, IN16 miles from this station, 49.9°F a year
- Logansport, IN17 miles from this station, 51.0°F a year
- Young America, IN17 miles from this station, 50.1°F a year
- West Lafayette, IN20 miles from this station, 50.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made