Ansonia, Connecticut climate: Normal weather by month, frost dates and records
Ansonia's normal year runs from 18°F January nights to 82°F July afternoons, with 52.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.1°C, January lows of −8°C, July highs of 28°C, 1,322 mm of precipitation a year.
- NOAA stationAnsonia (1 mi NE)
- Station IDUSC00060128
- Location41.35°N 73.09°W
- Elevation136 ft (42 m)
- From the center1 miles
- Population19,195
On October 23, the normal high in Ansonia is 61°F and the normal low 39°F, and the chance of measurable rain or snow is 26%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Ansonia.
- Jan 36° 18°
- Feb 38° 19°
- Mar 47° 27°
- Apr 58° 38°
- May 69° 47°
- Jun 77° 58°
- Jul 82° 63°
- Aug 82° 62°
- Sep 75° 54°
- Oct 63° 41°
- Nov 52° 32°
- Dec 41° 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 Ansonia each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 18°F. The most precipitation falls in October (5.00 in), the least in February (3.62 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 36°F | 18°F | 27.2°F | 3.95 | 9 | <1 | 27 | 9 h 30 min |
| February | 38°F | 19°F | 28.5°F | 3.62 | 7 | <1 | 25 | 10 h 40 min |
| March | 47°F | 27°F | 37.1°F | 4.72 | 9 | <1 | 24 | 11 h 50 min |
| April | 58°F | 38°F | 47.9°F | 4.72 | 10 | <1 | 8 | 13 h 20 min |
| May | 69°F | 47°F | 58.1°F | 4.04 | 11 | <1 | <1 | 14 h 30 min |
| June | 77°F | 58°F | 67.6°F | 3.93 | 10 | 1 | <1 | 15 h 10 min |
| July | 82°F | 63°F | 72.6°F | 4.30 | 9 | 4 | <1 | 14 h 50 min |
| August | 82°F | 62°F | 72.1°F | 4.56 | 8 | 3 | <1 | 13 h 50 min |
| September | 75°F | 54°F | 64.3°F | 4.38 | 8 | 1 | <1 | 12 h 30 min |
| October | 63°F | 41°F | 52.3°F | 5.00 | 8 | <1 | 3 | 11 h 10 min |
| November | 52°F | 32°F | 41.8°F | 4.24 | 8 | <1 | 19 | 9 h 50 min |
| December | 41°F | 23°F | 32.3°F | 4.57 | 9 | <1 | 24 | 9 h 10 min |
| Year (annual) | 60°F | 40°F | 50.1°F | 52.03 | 106 | 10 | 130 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 2°C | −8°C | −2.7°C | 100 mm |
| February | 3°C | −7°C | −1.9°C | 92 mm |
| March | 8°C | −3°C | 2.8°C | 120 mm |
| April | 15°C | 3°C | 8.8°C | 120 mm |
| May | 21°C | 8°C | 14.5°C | 103 mm |
| June | 25°C | 14°C | 19.8°C | 100 mm |
| July | 28°C | 17°C | 22.6°C | 109 mm |
| August | 28°C | 17°C | 22.3°C | 116 mm |
| September | 24°C | 12°C | 17.9°C | 111 mm |
| October | 17°C | 5°C | 11.3°C | 127 mm |
| November | 11°C | 0°C | 5.4°C | 108 mm |
| December | 5°C | −5°C | 0.2°C | 116 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Bridgeport (13 miles away), gets 34 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00060128; 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 Ansonia?
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 (8).
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 USC00060128.
When is the last frost in Ansonia?
In Ansonia, the last spring frost (32°F) comes after April 25 in half of years and after May 10 in one year in ten; the first autumn frost comes before October 17 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 251 year in 10 after May 10; 9 in 10 after April 11
- First autumn frost, half of years before
- October 171 year in 10 before October 4; 9 in 10 before November 1
NOAA puts the median frost-free season at 175 days, and the season without a hard freeze (28°F) at 202 days.
A hard freeze (28°F) comes after April 10 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Ansonia in zone 6b in ZIP code 06401.
Frost dates for every NOAA station in Connecticut · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00060128; 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 Ansonia?
In a normal year in Ansonia, 10 days a year reach 90°F, 130 nights fall to 32°F or colder and 106 days bring measurable precipitation.
- Days at 90°F or more
- 10a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 130a normal year
- Days that stay below freezing
- 21high of 32°F or less
- Days with 0.01 inch of precipitation
- 106a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00060128.
How sunny is Ansonia?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Ansonia, 3.9 kWh per square metre a day. July is the sunniest month (79%) and December the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 68% | 1.8 |
| February | 70% | 2.7 |
| March | 68% | 3.7 |
| April | 69% | 4.8 |
| May | 69% | 5.4 |
| June | 74% | 5.9 |
| July | 79% | 6.0 |
| August | 78% | 5.3 |
| September | 77% | 4.3 |
| October | 70% | 2.9 |
| November | 70% | 2.0 |
| December | 65% | 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 Ansonia need?
A normal year in Ansonia brings 6,070 heating degree days, 13% more than the median U.S. place (5,373), and 686 cooling degree days, 24% 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 2,823 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,172 | 0 |
| February | 1,022 | 0 |
| March | 865 | 0 |
| April | 516 | 1 |
| May | 232 | 18 |
| June | 39 | 116 |
| July | 3 | 237 |
| August | 6 | 224 |
| September | 107 | 86 |
| October | 398 | 3 |
| November | 696 | 0 |
| December | 1,015 | 0 |
| Year (annual) | 6,070 | 686 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00060128. 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 Ansonia's climate compare?
Ansonia is warmer than 5 of the other 12 places with their own NOAA record in Connecticut, and wetter than 10. Across the 7,247 U.S. stations with normals, its annual mean of 50.1°F is warmer than 40%.
In the Köppen classification computed from these normals, Ansonia 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 Ansonia share this climate record?
11 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.
- Shelton, CT42,805 people · 4 mi SW
- Orange, CT14,431 people · 6 mi SE
- Derby, CT12,915 people · 2 mi S
- Sandy Hook, CT9,718 people · 9 mi NW
- Daniels Farm, CT5,995 people · 8 mi SW
- Heritage Village, CT4,517 people · 12 mi NW
- Oronoque, CT3,908 people · 6 mi S
- East Village, CT3,744 people · 5 mi W
- Stepney, CT3,489 people · 9 mi W
- Tashua, CT3,436 people · 10 mi SW
- Botsford, CT702 people · 9 mi W
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 Ansonia's climate
What is the coldest month in Ansonia?
January, with a normal high of 36°F and a normal low of 18°F. The warmest is July (82°F by day, 63°F at night).
Does it snow in Ansonia?
Yes. NOAA publishes no 1991-2020 snowfall normal for Ansonia's NOAA station; the nearest record that keeps one, Bridgeport (13 miles away), records 34 inches of snow in a normal year.
What is the rainiest month in Ansonia?
October, with 5.00 in of precipitation in a normal year; the driest is February with 3.62 in.
What plant hardiness zone is Ansonia in?
The USDA's 2023 map puts Ansonia in zone 6b in ZIP code 06401.
How late can frost come in Ansonia?
In half of years the last 32°F night comes after April 25; in one year in ten it comes after May 10. Waiting until May 10 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Connecticut climateThe statewide normals and every place in the state
- Mount Carmel, CT11 miles from this station, 51.7°F a year
- New Haven, CT12 miles from this station, 52.0°F a year
- Bridgeport, CT13 miles from this station, 53.4°F a year
- Meriden, CT17 miles from this station, 50.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made