Johnstown weather in May: Johnstown, Pennsylvania: normal highs, lows, rain and records for May
Johnstown in May has a normal high of 68°F and a normal low of 49°F, a daily mean of 59°F, rising from 64°F on the 1st to 72°F by the 31st. Measurable precipitation falls on 17 days in a normal May, 4.12 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 20°C and low of 9°C, 105 mm of precipitation in May.
- NOAA stationJohnstown Cambria County Airport
- Station IDUSW00004726
- Location40.32°N 78.83°W
- Elevation2,284 ft (696 m)
- From the center5 miles
- Population17,853
- Jan 33° 19°
- Feb 36° 21°
- Mar 45° 28°
- Apr 58° 38°
- May 68° 49°
- Jun 75° 57°
- Jul 79° 61°
- Aug 77° 60°
- Sep 71° 53°
- Oct 59° 43°
- Nov 47° 33°
- Dec 38° 25°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Johnstown in May?
The normal high is 68°F and the normal low 49°F, for a daily mean of 58.5°F. May is 10.4°F warmer than April and 7.5°F cooler than June. May is the 5th warmest month of the year in Johnstown and the 3rd wettest. Across the month the normal high rises 8°F, from 64°F on May 1 to 72°F on May 31. From one year to the next May's mean temperature typically moves about 3.5°F either way (NOAA's standard deviation), so roughly two Mays in three average between 55°F and 62°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 54%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 64°F | 44°F | 50% | 31% |
| May 8 | 66°F | 46°F | 52% | 32% |
| May 15 | 68°F | 49°F | 54% | 33% |
| May 22 | 70°F | 51°F | 54% | 32% |
| May 31 | 72°F | 53°F | 52% | 32% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 64°F | 44°F | 50% | 31% | 13 h 50 min |
| May 2 | 65°F | 45°F | 51% | 32% | 14 h |
| May 3 | 65°F | 45°F | 51% | 32% | 14 h |
| May 4 | 65°F | 45°F | 51% | 32% | 14 h |
| May 5 | 66°F | 46°F | 51% | 32% | 14 h |
| May 6 | 66°F | 46°F | 52% | 32% | 14 h |
| May 7 | 66°F | 46°F | 52% | 32% | 14 h 10 min |
| May 8 | 66°F | 46°F | 52% | 32% | 14 h 10 min |
| May 9 | 67°F | 47°F | 53% | 32% | 14 h 10 min |
| May 10 | 67°F | 47°F | 53% | 33% | 14 h 10 min |
| May 11 | 67°F | 47°F | 53% | 33% | 14 h 20 min |
| May 12 | 67°F | 48°F | 54% | 33% | 14 h 20 min |
| May 13 | 68°F | 48°F | 54% | 33% | 14 h 20 min |
| May 14 | 68°F | 48°F | 54% | 33% | 14 h 20 min |
| May 15 | 68°F | 49°F | 54% | 33% | 14 h 20 min |
| May 16 | 68°F | 49°F | 54% | 33% | 14 h 20 min |
| May 17 | 69°F | 49°F | 54% | 33% | 14 h 30 min |
| May 18 | 69°F | 49°F | 54% | 33% | 14 h 30 min |
| May 19 | 69°F | 50°F | 54% | 33% | 14 h 30 min |
| May 20 | 69°F | 50°F | 54% | 32% | 14 h 30 min |
| May 21 | 69°F | 50°F | 54% | 32% | 14 h 30 min |
| May 22 | 70°F | 51°F | 54% | 32% | 14 h 40 min |
| May 23 | 70°F | 51°F | 54% | 32% | 14 h 40 min |
| May 24 | 70°F | 51°F | 54% | 32% | 14 h 40 min |
| May 25 | 70°F | 52°F | 53% | 32% | 14 h 40 min |
| May 26 | 70°F | 52°F | 53% | 32% | 14 h 40 min |
| May 27 | 71°F | 52°F | 53% | 32% | 14 h 40 min |
| May 28 | 71°F | 52°F | 53% | 32% | 14 h 40 min |
| May 29 | 71°F | 53°F | 53% | 32% | 14 h 50 min |
| May 30 | 71°F | 53°F | 53% | 32% | 14 h 50 min |
| May 31 | 72°F | 53°F | 52% | 32% | 14 h 50 min |
- Normal high
- 68°FMay average
- Normal low
- 49°FMay average
- Precipitation
- 4.12 inmonth total
- Days with precipitation
- 170.01 inch or more
- Nights at 32°F or colder
- 1
- Daylight
- 13 h 50 min to 14 h 50 minMay 1 to May 31
- Days at 70°F or more
- 13
- Days at 80°F or more
- 3
- Sunshine
- 67%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00004726; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Johnstown in May?
On a given May day the chance of 0.01 inch or more is 53% on average, highest around May 15 (54%). In all, 4.12 in falls on 17 days of a normal May, 1 of them with an inch or more.
In a normal May in Johnstown, 1 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00004726.
How humid and windy is Johnstown in May?
At 3 p.m. the normal temperature is 69°F with 55% relative humidity and a dew point of 52°F; at 6 a.m. it is 56°F with 83% humidity. The wind averages 7.9 mph, most often from the west in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 56°F | 51°F | 83% | 6.5 mph | – |
| 9 a.m. | 62°F | 53°F | 71% | 8.1 mph | – |
| noon | 67°F | 53°F | 59% | 9.3 mph | – |
| 3 p.m. | 69°F | 52°F | 55% | 10.1 mph | – |
| 6 p.m. | 67°F | 52°F | 60% | 8.8 mph | – |
| 9 p.m. | 61°F | 52°F | 71% | 7.0 mph | – |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00004726. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for May in Johnstown?
The warmest May temperature on this station's record (since 2000) is 87°F, on May 30, 2006; the coldest is 23°F, on May 9, 2020. The wettest May brought 8.69 in (2025).
The May mean against the 1991-2020 normal of 58.5°F: 2021 56.1°F (−2.4), 2022 59.7°F (+1.2), 2023 56.0°F (−2.5), 2024 61.4°F (+2.9), 2025 56.8°F (−1.7), 2026 55.0°F (−3.5). 2 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 56.1°F | −2.4°F | 4.39 in |
| 2022 | 59.7°F | +1.2°F | 5.52 in |
| 2023 | 56.0°F | −2.5°F | 2.96 in |
| 2024 | 61.4°F | +2.9°F | 5.13 in |
| 2025 | 56.8°F | −1.7°F | 8.69 in |
| 2026 | 55.0°F | −3.5°F | 5.03 in |
Source: records: ACIS, station USW00004726; recent months: ACIS, station USW00004726. Records and recent months use complete months only.
How does May in Johnstown compare across Pennsylvania?
Across the 108 places PlainClimate covers in Pennsylvania, May normal highs run from 65°F in Laporte to 75°F in Phoenixville; Johnstown's is 68°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.