Weather in Allentown

Planning a trip or just curious about the weather in Allentown? Here you will find the most up-to-date information: current weather conditions, detailed forecasts, and clear charts.

Allentown, located in the United States, is characterized by a temperate continental climate with four distinct seasons. The weather here is quite variable throughout the year, allowing you to enjoy the charms of every season, from snowy winters to warm summers.

Summer in Allentown is generally warm and sunny, with average temperatures in July and August reaching 23-24°C, while maximum values can approach 30°C. Winters, on the other hand, are cold, with average temperatures around 0°C in January and December, and night frosts. Spring and autumn are transitional seasons with pleasant, moderate weather, gradually changing from cool to warm and back again.

Precipitation in Allentown is distributed quite evenly throughout the year, with an average amount of about 3-4 mm per month. The number of rainy days is also relatively constant, varying from 9 to 14 days per month. This means that when planning a trip, it is worth being prepared for possible precipitation at any time of the year, whether it be rain or snow during the winter months.

Allentown experiences distinct seasonal temperature changes throughout the year. The coldest month is typically January, when the average air temperature hovers around the 0.2°C mark. During this period, average minimum night temperatures drop to -3.4°C, and daytime highs rarely exceed 3.8°C. December is also cold, with an average temperature of 2.2°C and minimum values around -1.3°C. On the other hand, the peak of summer heat occurs in July, when the average temperature reaches 24.6°C, and daytime highs often rise to 29.5°C. August follows closely behind, offering an average temperature of 23.2°C and maximum daytime values around 27.8°C.

The summer months in Allentown, spanning from June to August, are characterized by warm, and at times hot, weather. The average daily temperature in June is 21.2°C, rising to 24.6°C in July. Daytime temperatures in this season consistently exceed 25°C, creating comfortable conditions for a summer holiday, although it can sometimes be quite sultry. Winter, including December, January, and February, brings cool and frosty weather. Average daytime temperatures range from 3.8°C in January to 6.2°C in February. Night frosts are a common occurrence, especially in January, when the thermometer drops on average to -3.4°C, and in February (-2.5°C).

The spring and autumn months serve as transitional periods with more moderate temperatures. In spring, the temperature gradually increases: from an average of 5.3°C in March (with lows around 0.6°C and highs up to 10.1°C) to 16.6°C in May (minimum 11.2°C, maximum 21.9°C). In autumn, the reverse trend is observed: in September, the average temperature is a comfortable 19.6°C, gradually decreasing to 6.7°C in November. Throughout the year, noticeable daily temperature fluctuations are recorded in Allentown. The difference between daytime highs and nighttime lows often ranges from 7°C in the coldest months to nearly 11°C in mid-spring, making evenings and nights noticeably cooler even after warm days.

In Allentown, the nature of precipitation changes noticeably depending on the time of year. Winter months, especially January (average temperature 0.2°C), February (1.8°C), and December (2.2°C), often bring snowfall, as minimum temperatures drop below freezing at this time. In transitional periods, such as March (with an average temperature of 5.3°C) and November (6.7°C), both rain and the first or last snow are possible. From April to October, when warm weather sets in, precipitation falls mainly in the form of rain.

Regarding the frequency and volume of precipitation, the highest number of days with precipitation falls in July (an average of 14 days), followed by June and August (13 days each). November stands out as the month with the fewest rainy days — an average of 9. Although the difference in total monthly rainfall is small (3-4 mm), months such as February, April, May, July, August, September, and December receive slightly more moisture (4 mm) compared to January, March, June, October, and November (3 mm). Thus, travellers should be prepared for the likelihood of precipitation in almost any season, but its nature will vary.

When planning a trip to Allentown, it is important to consider the changing seasons so that your wardrobe matches the weather. The climate here is characterized by four distinct seasons. Regardless of the time of year, comfortable walking shoes will be your best companion, as the city is conducive to walking. The principle of layering in clothing is the key to comfort, allowing you to easily adapt to temperature changes throughout the day. A small umbrella or a light waterproof jacket will also be useful, as precipitation is possible year-round, averaging 10-14 days a month with a small amount of rainfall (3-4 mm).

In winter (from December to February), it can be quite cold in Allentown, with the average temperature fluctuating around 0-2°C, and night frosts being a common occurrence. You will need a warm jacket, sweaters, a hat, gloves, and a scarf. Waterproof shoes will also be handy, especially if it snows. Summer (from June to August) is warm and at times hot, with average temperatures of 21-25°C, while maximums can reach nearly 30°C. For this period, choose light, breathable clothing, t-shirts, shorts, and sundresses. Do not forget sunscreen and a hat for sun protection, especially if you plan to spend a lot of time outdoors.

Spring (March-May) and autumn (September-November) are transitional seasons with changeable weather. The temperature in spring gradually rises from 5°C to 16°C, while in autumn, conversely, it drops from a comfortable 19°C to 6°C. During these months, the principle of layering is especially relevant: light jackets, cardigans, and jumpers that can be taken off or put on depending on the weather. Jeans or comfortable trousers, as well as closed shoes, will be a good choice. Checking the weather forecast right before your trip will help you adjust your luggage more precisely.