Weather in Trenton, New Jersey
Roses open along the stoops. Day 59 of spring. Read this microseason across nine climate regions →
- TodayMay 16Overcast—83°46°
- SundayMay 17Overcast—91°62°
- MondayMay 18Overcast—96°64°
- TuesdayMay 19Drizzle—95°70°
- WednesdayMay 20Showers53%92°60°
- ThursdayMay 21Overcast47%76°51°
- FridayMay 22Drizzle30%62°49°
- PM 2.5
- 9.7 μg/m³
- PM 10
- 10.1 μg/m³
- NO₂
- 11.0 μg/m³
- Ozone
- 106.0 μg/m³
- UV Index
- 0.0 Low
When the dew is on the grass, rain will never come to pass.
- Moonrise
- 9:46 AM
- Moonset
- 12:36 AM
- In sign
- ♊︎ Gemini
Roses open along the stoops
Trenton at a glance
- Today vs. normal: 72°F — typical for the season
- Last frost: April 17 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Warm-season window is open
As of May 17, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.
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.