Grantley, Pennsylvania Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Grantley weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Light Rain33%0.05″101°75°—
- SundayJul 5Heavy Rain90%0.31″96°72°-5°
- MondayJul 6Heavy Drizzle90%0.12″75°63°-21°
- TuesdayJul 7Light Drizzle71%0.01″70°59°-5°
- WednesdayJul 8Partly Cloudy13%—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 6 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 6 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
Grantley at a glance
- Today vs. normal: 12°F above the seasonal normal for this latitude
- Last frost: April 16 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Grantley
- Sat101°75°33%
- Sun96°72°90%
- Mon75°63°90%
- Tue70°59°71%
- Wed83°55°13%
- Thu89°67°26%
- Fri89°69°42%
- Sat87°70°35%
- Sun74°65°27%
- Mon70°63°17%
- Tue75°64°11%
- Wed86°67°24%
- Thu92°70°26%
- Fri93°72°35%
- Sat79°70°42%
- Sun85°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 — Grantley
SPC has placed Grantley 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
Grantley's warmest month is July (~77°F mean) and its coldest is January (~30°F). Rainfall peaks in December (3.8 inches) and bottoms out in February (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
Per NOAA NCEI 1991-2020 normals, Grantley runs from a 30°F January mean to 77°F in July, a 47°F seasonal spread, with near 40.2 inches of precipitation across about 182 wet days.
Grantley's precipitation spreads evenly: December peaks at 3.8 inches on 14.2 wet days, while February holds 2.7 inches over 13.0 — no month dominates Grantley's rain calendar. That lines Grantley up with places like Tyler Run, PA, Valley View, PA and York, PA, fed by overlapping storm tracks.
Grantley reaches its last hard frost near mid-April; that is the cue for kale, peas, spinach, and parsnips. Heat-demanding starts go out a fortnight on in Grantley, after the soil warms and cold snaps clear. The season ends by mid-November in Grantley, once hard frosts set back in. Grantley's low ground holds frost later into spring than Grantley's benches, which run 3-5 days ahead.
Similar climates: Tyler Run, PA, Valley View, PA, York, PA, West York, PA, Queens Gate, PA.
Frequently asked
- When does it freeze in Grantley?
- Frost typically leaves Grantley by mid-April and returns to Grantley near mid-November.
- What is the rainy season in Grantley?
- Rainfall in Grantley peaks in December near 3.8 inches, out of about 40 inches annually.
- What is the warmest month in Grantley?
- On average July tops the year in Grantley at about 77°F.
- What is the coldest month in Grantley?
- The coldest stretch in Grantley falls in January, around 30°F on average.
- When can I start a vegetable garden in Grantley?
- In Grantley, sow peas and hardy greens around mid-April; Grantley's tomatoes and peppers wait two weeks more.
- How many rainy days does Grantley get?
- Grantley averages about 182 days with measurable rain or snow each year.
- What hardiness zone is Grantley?
- With January around 30°F, Grantley's zone reflects that minimum — the USDA ZIP map confirms Grantley's band.
- What is the 10-day forecast for Grantley?
- Grantley'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 Grantley?
- See this week's day-by-day rain chances for Grantley in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Grantley?
- Current conditions for Grantley and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Grantley forecast updated?
- The Grantley forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Grantley?
- Today's sunrise and sunset times for Grantley 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 Grantley?
- The next few days in Grantley's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
In Grantley, Pennsylvania, the warm-summer humid continental climate runs from about 30°F in January to 77°F in July, a 47°F seasonal range.
Grantley sees close to 40 inches of precipitation annually, falling across some 182 wet days.
Grantley's 47°F range, set by its 39.9°N position, drives frost timing and what thrives in Grantley.
ZIP codes in Grantley
- 17403