Hartford, Connecticut Weather
Fireflies rise from the lawn. Day 78 of spring. Read this microseason across nine climate regions →
Hartford weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Clear——89°53°—
- FridayJun 5Overcast——91°62°+2°
- SaturdayJun 6Light Drizzle41%—92°63°+1°
- SundayJun 7Drizzle41%0.02″84°59°-8°
- MondayJun 8Overcast——85°50°+1°
- TuesdayJun 9Overcast——90°58°+5°
- WednesdayJun 10Overcast10%—96°61°+6°
PM2.5 at 12.5 µg/m³, PM10 at 13.7 µg/m³ — typical background levels with no transport signature. AQI up 22 in the last 6 hours — air quality is degrading.
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 44. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 44
- UV peak
- 0.0 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 5
PM × Wind × Precip
PM2.5 at 12.5 µg/m³, PM10 at 13.7 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.91
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- background
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).
The higher the clouds, the finer the weather.
- Moonrise
- 3:54 AM
- Moonset
- 1:50 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Hartford at a glance
- Today vs. normal: 73°F — typical for the season
- Last frost: April 27 (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 5, 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.
SPC Convective Outlook
Storm Prediction Center — Hartford
SPC has placed Hartford in the Marginal Risk category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3MRGLMarginal Risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
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 Hartford's warmest temperatures (~75°F mean) while January delivers the coldest (~29°F). Rainfall reaches its peak in October (4.2 inches) and hits its lowest point in February (2.6 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 29° | 2.9″ | 6 |
| February | 31° | 2.6″ | 6 |
| March | 39° | 3.5″ | 7 |
| April | 50° | 3.8″ | 6 |
| May | 61° | 3.4″ | 7 |
| June | 70° | 3.9″ | 6 |
| July | 75° | 3.9″ | 7 |
| August | 74° | 3.5″ | 6 |
| September | 66° | 4.0″ | 5 |
| October | 54° | 4.2″ | 6 |
| November | 43° | 3.4″ | 6 |
| December | 34° | 3.8″ | 8 |
Regional context
Hartford belongs to a warm-summer humid continental climate region, sharing similar temperature ranges, seasonal patterns, and growing conditions with nearby cities in this climate zone.
Similar climates: Bridgeport, CT, New Haven, CT, Waterbury, CT, Danbury, CT, Norwich, CT.
Naturalist notes
Red maple buds begin swelling in late March as daylight hours lengthen past winter's grip.
American robins return to Hartford lawns in early April, their arrival coinciding with soil temperatures that awaken earthworms.
Frequently asked
- When does it freeze in Hartford?
- Hartford's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Hartford?
- October is the wettest month with about 4.2 inches of rain on average; the city receives roughly 43 inches annually.
- What is the warmest month in Hartford?
- July is typically warmest, averaging about 75°F.
- What is the coldest month in Hartford?
- January is typically coldest, averaging about 29°F.
- When can I start a vegetable garden in Hartford?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-April); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Hartford get?
- Hartford averages about 76 rainy days per year.
- What hardiness zone is Hartford?
- Hartford's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Hartford, Connecticut experiences a warm-summer humid continental climate zone. January temperatures typically hover near 29°F while July averages 75°F, creating a 47°F seasonal swing.
Throughout the year, Hartford receives about 43 inches of precipitation spread over roughly 76 rainy days.
Location drives the weather patterns here: latitude (41.8°N), proximity to large water bodies, and elevation determine what grows, when frost arrives, and how daily weather unfolds.