New Haven, Connecticut Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
New Haven weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——85°56°—
- FridayJun 5Overcast——86°57°+1°
- SaturdayJun 6Light Drizzle39%—84°66°-2°
- SundayJun 7Heavy Drizzle60%0.06″84°63°0°
- MondayJun 8Overcast23%—72°57°-12°
- TuesdayJun 9Overcast——80°57°+8°
- WednesdayJun 10Overcast——77°59°-3°
Ozone at AQI 48 now. AQI up 6 over the last 6 hours (gradual rise). With UV 3.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 21 by mid-afternoon.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 48 now. With UV 3.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 21 by mid-afternoon.
- Present
- AQI 48
- UV peak
- 3.3 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 21
PM × Wind × Precip
PM2.5 at 6.4 µg/m³ (AQI 36) with a 0.75 fine-to-coarse ratio and 4 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.75
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 3:23 AM
- Moonset
- 12:46 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
New Haven at a glance
- Today vs. normal: 13°F below the seasonal normal for this latitude
- Last frost: April 24 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
July brings New Haven's warmest temperatures at around 74°F mean, while January delivers the coldest at roughly 31°F. April sees peak rainfall with 4.2 inches, contrasting with January's drier 2.7 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 31° | 2.7″ | 5 |
| February | 32° | 2.8″ | 6 |
| March | 39° | 3.7″ | 6 |
| April | 49° | 4.2″ | 7 |
| May | 59° | 3.5″ | 7 |
| June | 68° | 3.5″ | 7 |
| July | 74° | 3.4″ | 6 |
| August | 73° | 3.5″ | 6 |
| September | 66° | 4.0″ | 5 |
| October | 55° | 3.8″ | 7 |
| November | 45° | 3.1″ | 6 |
| December | 36° | 3.5″ | 7 |
Regional context
Located in a warm-summer humid continental climate region, New Haven shares temperature ranges, seasonal patterns, and growing conditions with other nearby cities in this climate zone.
Similar climates: Hartford, CT, Bridgeport, CT, Waterbury, CT, Danbury, CT, Norwich, CT.
Naturalist notes
Late May brings the arrival of ruby-throated hummingbirds to New Haven gardens and parks.
By mid-June, common milkweed begins its distinctive pink-purple bloom across Connecticut meadows.
Frequently asked
- When does it freeze in New Haven?
- Spring's final frost usually occurs around mid-April in New Haven, while the first fall frost typically arrives around mid-November.
- What is the rainy season in New Haven?
- April stands as the wettest month, delivering about 4.2 inches of rain on average, while the city's annual total reaches roughly 42 inches.
- What is the warmest month in New Haven?
- July typically brings the warmest weather, with temperatures averaging about 74°F.
- What is the coldest month in New Haven?
- January usually delivers the coldest conditions, averaging about 31°F.
- When can I start a vegetable garden in New Haven?
- Cool-season crops like peas and lettuce can go into the ground around the last spring frost in mid-April, while warm-season varieties such as tomatoes and peppers should wait 1–2 weeks after that date.
- How many rainy days does New Haven get?
- New Haven typically experiences about 74 rainy days each year.
- What hardiness zone is New Haven?
- New Haven's USDA hardiness zone depends on its lowest average winter temperature; the USDA's online lookup tool can provide the current zone designation using the city ZIP.
Climate
New Haven, Connecticut experiences a warm-summer humid continental climate. January temperatures hover near 31°F while July averages reach 74°F, creating a 43°F seasonal swing.
Annual precipitation totals about 42 inches across roughly 74 rainy days throughout the year.
Weather patterns here depend on the city's latitude at 41.3°N, its proximity to large water bodies, and local elevation. These factors determine growing seasons, frost timing, and daily weather conditions.