Allentown, PA weather in May
Expect mild weather with frequent rain in Allentown in May, with highs near 74°F and lows near 51°F. Rain falls on about 12 days.
- Normal high
- 74°F
- Normal low
- 51°F
- Wet days
- 12
- 3.6 in total
- Muggy days
- 1
- dew point 65°F+
How May changes from start to finish
| May 1 | May 31 | |
|---|---|---|
| Normal high | 69°F | 77°F |
| Normal low | 46°F | 55°F |
| Chance of a wet day | 39% | 40% |
| Sunrise / sunset | 6:00 am / 7:57 pm | 5:33 am / 8:25 pm |
| Daylight | 13.9 h | 14.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical May day
- 6 am54°Fdew point 48°F
- 9 am62°Fdew point 49°F
- Noon68°Fdew point 49°F
- 3 pm70°Fdew point 48°F
- 6 pm68°Fdew point 48°F
- 9 pm61°Fdew point 48°F
NOAA hourly normals (local standard time) from Allentown Intl Airport (4 mi away); average wind 7 mph; clear or few clouds in 51% of daytime hours, mostly cloudy or overcast in 40%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F16 of 31
- Hot dayshigh 90°F or more1 of 31
- Muggy daysdaily mean dew point 65°F or more1 of 31
- Wet daysat least 0.01 in of rain or melted snow12 of 31
- Notable rainat least 0.10 in8 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per May, counted from daily records for each year 1991-2020.
Rain in May
Normal precipitation is 3.6 in; a dry May brings about 2.7 in and a wet one about 4.4 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How May varies from year to year
- Warmest May, 1991-20202015: average high 80°F
- Coolest May2003: average high 66°F
- Wettest May2019: 9.1 in
- Driest May2015: 0.8 in
- Highest reading94°F (May 31, 2013)
- Lowest reading29°F (May 14, 1996)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
May compared with April and June
| April | May | June | |
|---|---|---|---|
| Normal high | 63°F | 74°F | 82°F |
| Normal low | 40°F | 51°F | 60°F |
| Wet days | 12 | 12 | 11 |
| Comfortable days | 11 | 16 | 9 |
| Daylight | 13.3 h | 14.4 h | 15.0 h |
Highs change by +11°F from April and +8°F into June.
Nearby alternatives in May
- Cooler: Bridgeport, CT125 mi · high 68°F · 12 wet days
How Allentown ranks in May
- Normal high217th warmest of 378 cities; 2nd of 4 in Pennsylvania
- Wet days298th driest of 378
- Comfortable days75th most of 339
What to pack for Allentown in May
- A rain jacket or umbrella – rain on about 12 days
Heating and cooling
May has 151 heating degree days and 60 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Allentown in May?
The normal high is 74°F and the normal low is 51°F. From 1991 to 2020 the hottest May reading was 94°F (May 31, 2013).
Does it rain a lot in Allentown in May?
About 12 days in May have at least 0.01 in of precipitation, and the normal total is 3.7 in. The wettest May in 1991-2020 was in 2019 (9.1 in); the driest was in 2015 (0.8 in).
Is May a good time to visit Allentown?
May ranks 1st of 12 months on our comfort score for Allentown (72 out of 100). It has about 16 comfortable days and about 1 day at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth, frost dates, humidity and wind by hour and cloud cover: Allentown Intl Airport (USW00014737), 3.6 mi NE of the city center, 390 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Lehigh Valley International Airport (725170-14737), 3.6 mi NE of the city center, 385 ft . Hourly observations, 1991-2020.