Weather in Jacobus, Pennsylvania
Roses open along the stoops. Day 59 of spring. Read this microseason across nine climate regions →
- TodayMay 16Overcast14%81°47°
- SundayMay 17Overcast11%85°60°
- MondayMay 18Showers—95°64°
- TuesdayMay 19Thunderstorm—87°62°
- WednesdayMay 20Showers83%84°57°
- ThursdayMay 21Overcast21%67°47°
- FridayMay 22Drizzle46%55°47°
- PM 2.5
- 6.5 μg/m³
- PM 10
- 6.7 μg/m³
- NO₂
- 6.7 μg/m³
- Ozone
- 76.0 μg/m³
- UV Index
- 0.0 Low
When the dew is on the grass, rain will never come to pass.
- Moonrise
- 9:54 AM
- Moonset
- 12:43 AM
- In sign
- ♊︎ Gemini
Roses open along the stoops
Jacobus at a glance
- Today vs. normal: 5°F below the seasonal normal for this latitude
- Last frost: April 15 (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
Jacobus's warmest month is July (~75°F mean) and its coldest is January (~31°F). Rainfall peaks in September (5.1 inches) and bottoms out in February (2.8 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 31° | 3.3″ | 6 |
| February | 34° | 2.8″ | 6 |
| March | 42° | 4.0″ | 7 |
| April | 54° | 3.6″ | 7 |
| May | 63° | 4.2″ | 8 |
| June | 71° | 4.3″ | 7 |
| July | 75° | 4.5″ | 7 |
| August | 74° | 4.0″ | 6 |
| September | 67° | 5.1″ | 6 |
| October | 56° | 3.9″ | 5 |
| November | 44° | 3.2″ | 6 |
| December | 36° | 3.5″ | 7 |
Regional context
Jacobus sits within a warm-summer humid continental climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Philadelphia, PA, Pittsburgh, PA, Allentown, PA, Harrisburg, PA, Lancaster, PA.
Frequently asked
- When does it freeze in Jacobus?
- Jacobus's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Jacobus?
- September is the wettest month with about 5.1 inches of rain on average; the city receives roughly 46 inches annually.
- What is the warmest month in Jacobus?
- July is typically warmest, averaging about 75°F.
- What is the coldest month in Jacobus?
- January is typically coldest, averaging about 31°F.
- When can I start a vegetable garden in Jacobus?
- 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 Jacobus get?
- Jacobus averages about 79 rainy days per year.
- What hardiness zone is Jacobus?
- Jacobus'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
Jacobus, Pennsylvania sits in a warm-summer humid continental climate zone. January means hover near 31°F while July averages 75°F — a 44°F seasonal swing.
Across the year, Jacobus receives about 46 inches of precipitation spread over roughly 79 rainy days.
The rhythm of the year is set by latitude (39.9°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.