Glen Lyon, Pennsylvania Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Glen Lyon weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——82°46°—
- FridayJun 5Overcast——85°57°+3°
- SaturdayJun 6Showers47%0.15″83°62°-2°
- SundayJun 7Light Showers47%—83°61°0°
- MondayJun 8Overcast——72°53°-11°
- TuesdayJun 9Overcast——79°50°+7°
- WednesdayJun 10Partly Cloudy15%—84°52°+5°
Ozone at AQI 85. AQI up 18 in the last 6 hours — air quality is degrading. Overcast through the UV peak window (cloud cover ~67%) — 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 85. Overcast through the UV peak window (cloud cover ~67%) — afternoon ozone should stay flat.
- Present
- AQI 85
- UV peak
- 8.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 47
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
- 3:36 AM
- Moonset
- 1:00 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Glen Lyon at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: April 23 (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 — Glen Lyon
SPC has placed Glen Lyon in the Marginal Risk category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3MRGLMarginal Risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
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
Glen Lyon's warmest month is July (~69°F mean) and its coldest is January (~25°F). Rainfall peaks in September (4.9 inches) and bottoms out in February (2.5 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 25° | 3.2″ | 6 |
| February | 27° | 2.5″ | 5 |
| March | 35° | 3.4″ | 7 |
| April | 46° | 4.4″ | 7 |
| May | 57° | 4.7″ | 9 |
| June | 65° | 4.5″ | 9 |
| July | 69° | 4.5″ | 9 |
| August | 68° | 4.5″ | 7 |
| September | 61° | 4.9″ | 7 |
| October | 50° | 4.8″ | 8 |
| November | 40° | 3.4″ | 5 |
| December | 30° | 3.6″ | 7 |
Regional context
Glen Lyon's baseline climate, derived from NOAA NCEI 1991-2020 normals at the nearest reporting station, swings from a January mean of 25°F to a July mean of 69°F — a 45°F seasonal arc typical of the mid-latitude bands. Annual precipitation runs about 48.4 inches spread across roughly 85 days with measurable rain or snow each year.
Precipitation runs summer-dominant here: September averages 4.9 inches across 6.6 days with measurable rain, driven mostly by warm-season storms and thunderstorm activity, while February drops to just 2.5 inches across 4.6 rainy days under drier cool-season air. That wet-warm-summer pattern groups Glen Lyon with places like Wanamie, PA, Sheatown, PA and Mocanaqua, PA — a regional cohort where summer thunderstorm season carries more than half the annual moisture.
The frost-sensitive growing window opens around mid-April, when overnight lows reliably clear freezing for cool-season crops like kale, peas, spinach, and parsnips. Warm-season transplants — tomatoes, peppers, and basil — typically wait two weeks past that date to avoid late spring cold snaps. The window closes around mid-November, when overnight lows resume dipping below freezing and frost-tender plants need protection or harvest. The dates above are 1991-2020 normals; in a given year either bookend can move 1-2 weeks either direction. Within Glen Lyon, low-lying parcels along drainage features typically lose 4-7°F of overnight low temperature versus the bench positions on calm clear nights, which shifts the working last-frost date by a week or more.
Similar climates: Wanamie, PA, Sheatown, PA, Mocanaqua, PA, Shickshinny, PA, Nanticoke, PA.
Frequently asked
- When does it freeze in Glen Lyon?
- Glen Lyon's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Glen Lyon?
- September is the wettest month with about 4.9 inches of rain on average; the city receives roughly 48 inches annually.
- What is the warmest month in Glen Lyon?
- July is typically warmest, averaging about 69°F.
- What is the coldest month in Glen Lyon?
- January is typically coldest, averaging about 25°F.
- When can I start a vegetable garden in Glen Lyon?
- 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 Glen Lyon get?
- Glen Lyon averages about 85 rainy days per year.
- What hardiness zone is Glen Lyon?
- Glen Lyon'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
Glen Lyon, Pennsylvania sits in a warm-summer humid continental climate zone. January means hover near 25°F while July averages 69°F — a 45°F seasonal swing.
Across the year, Glen Lyon receives about 48 inches of precipitation spread over roughly 85 rainy days.
The rhythm of the year is set by latitude (41.2°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.