Jacobus, Pennsylvania Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Jacobus weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Drizzle33%0.04″101°75°—
- SundayJul 5Rain90%0.24″96°72°-5°
- MondayJul 6Heavy Drizzle90%0.12″75°63°-21°
- TuesdayJul 7Light Drizzle71%0.01″70°59°-5°
- WednesdayJul 8Partly Cloudy14%—83°55°+13°
- ThursdayJul 9Overcast26%—89°67°+6°
- FridayJul 10Drizzle42%0.01″89°69°0°
AQI 54 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 9.5 µg/m³ (AQI 52) with a 0.93 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 6 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 49 now. With UV 4.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 28 around 1 PM.
- Present
- AQI 49
- UV peak
- 4.3 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 28
PM × Wind × Precip
PM2.5 at 9.5 µg/m³ (AQI 52) with a 0.93 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.93
- 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).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:00 PM
- Moonset
- 10:10 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Jacobus at a glance
- Today vs. normal: 11°F above the seasonal normal for this latitude
- Last frost: April 15 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Jacobus
- Sat101°75°33%
- Sun96°72°90%
- Mon75°63°90%
- Tue70°59°71%
- Wed83°55°14%
- Thu89°67°26%
- Fri89°69°42%
- Sat87°69°35%
- Sun74°65°27%
- Mon70°63°16%
- Tue75°64°11%
- Wed86°67°24%
- Thu91°70°26%
- Fri92°72°35%
- Sat79°70°42%
- Sun84°68°44%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 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 — Jacobus
SPC has placed Jacobus in the Slight Risk category for severe thunderstorms today.
- TODAYSLGTSlight Risk
- TOMORROWSLGTSlight Risk
- DAY 3TSTMGeneral Thunderstorms
Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.
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.
Microseason · July 1–5
Cicadas claim the afternoon
Annual cicada buzz begins, peaking in the heat of the day.
Day 185 of 365 · Wedge 37 of 72
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
The year in Jacobus tops out in July (~77°F) and dips lowest in January (~30°F), with December wettest at 3.8 inches and February driest at 2.7 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 30° | 3.1″ | 14 |
| February | 32° | 2.7″ | 13 |
| March | 41° | 3.4″ | 16 |
| April | 53° | 3.7″ | 17 |
| May | 62° | 3.8″ | 18 |
| June | 71° | 3.6″ | 16 |
| July | 77° | 2.9″ | 15 |
| August | 75° | 3.5″ | 17 |
| September | 69° | 3.3″ | 15 |
| October | 58° | 2.8″ | 13 |
| November | 44° | 3.6″ | 14 |
| December | 34° | 3.8″ | 14 |
Regional context
Drawing on NOAA NCEI 1991-2020 normals, Jacobus's January averages 30°F and July 77°F — 47°F apart — while precipitation totals roughly 40.2 inches over some 182 days.
Rainfall in Jacobus stays even across the calendar: December tops out at 3.8 inches over 14.2 rainy days, and February still logs 2.7 inches across 13.0 — a narrow range for Jacobus. That even rhythm groups Jacobus with places like Loganville, PA, Spry, PA and Tyler Run, PA.
By mid-April the frosts ease in Jacobus, opening the season for kale, peas, spinach, and parsnips. Hold Jacobus's tender crops — tomatoes, peppers, basil — until 10-14 days past Jacobus's last frost. It shuts near mid-November, when freezes return to Jacobus and tender plants need cover. Within Jacobus, cold-air pooling chills low spots by 5-10°F, shifting Jacobus's local frost dates.
Similar climates: Loganville, PA, Spry, PA, Tyler Run, PA, Seven Valleys, PA, Dallastown, PA.
Frequently asked
- When does it freeze in Jacobus?
- Jacobus's last spring frost lands near mid-April, and in Jacobus the first fall frost follows around mid-November.
- What is the rainy season in Jacobus?
- Rainfall in Jacobus peaks in December near 3.8 inches, out of about 40 inches annually.
- What is the warmest month in Jacobus?
- July is Jacobus's warmest month, averaging about 77°F.
- What is the coldest month in Jacobus?
- Jacobus bottoms out in January, with a mean near 30°F.
- When can I start a vegetable garden in Jacobus?
- Frost-hardy sowings begin at mid-April in Jacobus; warm-season starts follow two weeks on.
- How many rainy days does Jacobus get?
- Jacobus averages about 182 days with measurable rain or snow each year.
- What hardiness zone is Jacobus?
- Jacobus's USDA zone comes from its January mean (30°F); enter the ZIP on the USDA lookup for the number.
- What is the 10-day forecast for Jacobus?
- Jacobus's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Jacobus?
- See this week's day-by-day rain chances for Jacobus in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Jacobus?
- Current conditions for Jacobus and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Jacobus forecast updated?
- The Jacobus forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Jacobus?
- Today's sunrise and sunset times for Jacobus are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Jacobus?
- The next few days in Jacobus's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Jacobus's warm-summer humid continental climate in Pennsylvania pairs 30°F Januarys with 77°F Julys, 47°F apart across the seasons.
Across the year, Jacobus collects about 40 inches of precipitation over roughly 182 days with measurable rain or snow.
At 39.9°N, Jacobus's 47°F summer-to-winter swing sets when Jacobus's gardens wake and when frost returns.
ZIP codes in Jacobus
- 17407