Average weather, temperature, rainfall, sunshine hours
The climate of Allentown is
continental, with very cold winters and warm to hot summers, during which there are quite frequent thunderstorms.
The city is located in the eastern United States, in eastern Pennsylvania, along the Lehigh River. The nearby cities of Bethlehem and Easton are part of the metropolitan area.
The
average temperature of the coldest month (January) is of -1.1 °C (30 °F), that of the warmest month (July) is of 24.2 °C (76 °F). Here are the average temperatures.
Allentown - Average temperatures (1991-2020)| Month | Min (°C) | Max (°C) | Mean (°C) | Min (°F) | Max (°F) | Mean (°F) |
|---|
| January | -6 | 4 | -1.1 | 22 | 38 | 30.1 |
|---|
| February | -5 | 5 | 0.2 | 23 | 42 | 32.4 |
|---|
| March | -1 | 10 | 4.8 | 30 | 51 | 40.6 |
|---|
| April | 5 | 17 | 11 | 40 | 63 | 51.8 |
|---|
| May | 10 | 23 | 16.7 | 51 | 74 | 62 |
|---|
| June | 15 | 28 | 21.6 | 60 | 82 | 70.9 |
|---|
| July | 18 | 30 | 24.2 | 65 | 86 | 75.6 |
|---|
| August | 17 | 29 | 23.1 | 63 | 84 | 73.6 |
|---|
| September | 13 | 25 | 19.1 | 55 | 77 | 66.3 |
|---|
| October | 7 | 19 | 12.6 | 44 | 66 | 54.6 |
|---|
| November | 1 | 12 | 6.6 | 34 | 54 | 44 |
|---|
| December | -3 | 6 | 1.6 | 27 | 43 | 35 |
|---|
| Year | 6.1 | 17.5 | 11.75 | 42.9 | 63.5 | 53 |
|---|
amounts to 1,205 millimeters (47.4 inches) per year: it is therefore quite abundant. It ranges from 70 mm (2.8 in) in the driest month (February) to 135 mm (5.3 in) in the wettest (July). Here is the average precipitation.
Allentown - Average precipitation (1991-2020)| Month | Millimeters | Inches | Days |
|---|
| January | 85 | 3.3 | 11 |
|---|
| February | 70 | 2.8 | 10 |
|---|
| March | 90 | 3.5 | 11 |
|---|
| April | 95 | 3.7 | 12 |
|---|
| May | 95 | 3.7 | 12 |
|---|
| June | 110 | 4.3 | 11 |
|---|
| July | 135 | 5.3 | 11 |
|---|
| August | 115 | 4.5 | 10 |
|---|
| September | 125 | 4.9 | 10 |
|---|
| October | 105 | 4.1 | 10 |
|---|
| November | 80 | 3.1 | 9 |
|---|
| December | 100 | 3.9 | 12 |
|---|
| Year | 1205 | 47.4 | 129 |
|---|
, from late November to early March, is very cold. Snowfalls are frequent, and at times can be abundant. On average, 84 centimeters (33 inches) of snow fall per year.
Cold waves are intense, in fact, the temperature typically drops to -15 °C (5 °F) on the coldest nights of the year, and can drop to -20 °C (-4 °F) once every few years. The record cold, -26 °C (-15 °F), was set in January 1994.
However, there can also be short, fairly mild periods, with highs of 12/13 °C (54/55 °F) or more.
Summer, from June to August, is hot and quite sunny, although thunderstorms can break out in the afternoon.
However, there can sometimes be very hot and muggy periods. Typically, the temperature reaches 35/36 °C (95/97 °F) on the hottest days of the year, although the record is 40 °C (104 °F), set in July 2011.
Spring and autumn, from mid-March to May and from September to mid-November, are contrasted seasons, with fairly frequent rains and sudden changes in temperature. However, there are also stable and pleasant periods.
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Best Time
The best times to visit Allentown are spring and autumn, especially the months of May and September.
In October, typically peaking in the second and third week, you can admire the beautiful colors of the trees losing their leaves (the phenomenon called
fall foliage).