Trenton, New Jersey Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Trenton weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Clear——88°55°—
- FridayJun 5Overcast——94°62°+6°
- SaturdayJun 6Light Showers49%—91°68°-3°
- SundayJun 7Light Showers49%—85°68°-6°
- MondayJun 8Clear——80°57°-5°
- TuesdayJun 9Partly Cloudy——85°58°+5°
- WednesdayJun 10Overcast——91°64°+6°
Ozone at AQI 66. AQI up 53 in the last 6 hours — air quality is degrading. Overcast through the UV peak window (cloud cover ~97%) — afternoon ozone should stay flat.
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 66. Overcast through the UV peak window (cloud cover ~97%) — afternoon ozone should stay flat.
- Present
- AQI 66
- UV peak
- 0.2 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 8
PM × Wind × Precip
PM2.5 at 6.3 µg/m³ (AQI 35) with a 1.00 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 1.00
- Wind
- light
- 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
- 3:27 AM
- Moonset
- 12:58 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Trenton at a glance
- Today vs. normal: 10°F above the seasonal normal for this latitude
- Last frost: April 17 (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.
SPC Convective Outlook
Storm Prediction Center — Trenton
SPC has placed Trenton in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
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 Trenton's highest temperatures, averaging around 76°F, while January delivers the coldest conditions at roughly 31°F. Precipitation follows a different pattern, with July receiving the most rainfall at 4.8 inches and February seeing the least at 2.8 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 31° | 3.6″ | 7 |
| February | 33° | 2.8″ | 5 |
| March | 41° | 4.4″ | 8 |
| April | 52° | 3.6″ | 7 |
| May | 61° | 3.5″ | 7 |
| June | 71° | 4.7″ | 7 |
| July | 76° | 4.8″ | 6 |
| August | 74° | 4.3″ | 6 |
| September | 67° | 4.1″ | 7 |
| October | 55° | 4.0″ | 5 |
| November | 45° | 3.2″ | 6 |
| December | 35° | 4.3″ | 7 |
Regional context
The city falls within a warm-summer humid continental climate region, sharing temperature ranges, seasonal patterns, and growing conditions with other nearby cities in this climate zone.
Similar climates: Newark, NJ, Jersey City, NJ, Paterson, NJ, Elizabeth, NJ, Clifton, NJ.
Naturalist notes
Late May brings the arrival of migrating warblers to Trenton's parks and wooded areas, their songs filling the canopy as they search for insects among newly emerged leaves.
Cherry blossoms typically reach peak bloom in mid-April, coinciding with the last expected frost dates in the region.
Frequently asked
- When does it freeze in Trenton?
- The last spring frost in Trenton typically occurs around mid-April, while the first fall frost usually arrives around mid-November.
- What is the rainy season in Trenton?
- July receives the most rainfall, averaging about 4.8 inches, while the city's total annual precipitation reaches roughly 47 inches.
- What is the warmest month in Trenton?
- July typically records the highest temperatures, with averages around 76°F.
- What is the coldest month in Trenton?
- January brings the coldest temperatures, averaging about 31°F.
- When can I start a vegetable garden in Trenton?
- Cool-season crops like peas and lettuce can be planted around the last spring frost in mid-April, while warm-season crops such as tomatoes and peppers should wait until 1–2 weeks after.
- How many rainy days does Trenton get?
- The city experiences about 76 rainy days per year on average.
- What hardiness zone is Trenton?
- Trenton'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 code.
Climate
Trenton, New Jersey experiences a warm-summer humid continental climate. January temperatures typically hover near 31°F, while July averages reach 76°F, creating a 45°F seasonal swing.
Annual precipitation totals about 47 inches, distributed across roughly 76 rainy days throughout the year.
Location at 40.2°N latitude, along with proximity to large water bodies and local elevation, determines the rhythms of plant growth, frost timing, and daily weather patterns.