Climate and monthly weather forecast
Waltham, MA

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The climate of Waltham

Located in Massachusetts, USA, Waltham endures a humid continental climate with no dry season, officially known under the Köppen climate classification as Dfa. The area’s geographical positioning results in a diverse weather palette throughout the year, with noticeable variations between seasons and even within months.

The city experiences a wide range of monthly temperatures, from 21.6°F (-5.8°C) as the lowest in January, up to July's warm pinnacle of 82°F (27.8°C). Fluctuating humidity levels are also a staple mark of Waltham's weather, although the monthly averages tend to hover between 70% in April to 78% in February. Monthly rainfall figures stick around the 0.55" (14mm) in February to 0.87" (22mm) in April and November.

Standout weather conditions include the sunny periods in July and August, with an average of 10.3 and 10.5 sunshine hours, respectively. These are the months where daylight duration reaches its maximum, providing an ample window for outdoor activities. Conversely, December has the shortest daylight duration of just 9.1 hours.

The best time to visit Waltham

Mild temperatures and ample sunshine make late spring and summer the optimal time to visit Waltham. From April to August, temperatures normally lie between 55.9°F (13.3°C) and 81°F (27.2°C), providing warm yet comfortable conditions for sightseeing. During this period, the city receives between 8.2 hours to 10.5 hours of sunshine daily, ideal for making the most out of the long days.

The worst time to visit Waltham

Visiting Waltham during the first quarter of the year, specifically from January to March, may prove challenging due to the colder weather, with temperatures falling between 21.6°F (-5.8°C) and 43.3°F (6.3°C). The city also experiences increased snowfall during these months, amounting to 0.67" (17mm) in January, 0.94" (24mm) in February, and just below 1 inch in March.

Spring weather in Waltham

Waltham's spring lasts from March to May, ushering in a transition from the cold winter temperatures to warmer weather. In March, the temperatures lie between 29.7°F (-1.3°C) to 43.3°F (6.3°C), but by May they evolve, reaching a range from 49.6°F (9.8°C) to 66.9°F (19.4°C). Precipitation in this period is relatively high, with April providing the heaviest rainfall at 0.87" (22mm).

Summer weather in Waltham

During the summer, from June to August, Waltham enjoys warmer temperatures ranging from 81°F (27.2°C) in July to 71°F (21.7°C) in June. It's the least humid period of the year, with relative humidity fluctuating from 73% to 74%. This season also receives more sunshine than others, with July leading at 10.3 hours per day. The average r ainfall of 0.83" (21mm) in June, 0.75" (19mm) in July, and 0.67" (17mm) in August is indicative of relatively dry months.

Autumn weather in Waltham

Autumn comes with a gradual cooling trend from September to November. The temperatures start with a spread from 56.3°F (13.5°C) to 73.2°F (22.9°C) in September, tapering to between 28.6°F (-1.9°C) to 49.1°F (9.5°C) in November. Rainfall is also likely during this season, with November experiencing the maximum of 0.87" (22mm).

Winter weather in Waltham

Winters in Waltham can be quite chilly, with December to February temperatures ranging from 21.6°F (-5.8°C) to 36.1°F (2.3°C). It is also the period with the highest probability of snowfall, with 0.67" (17mm) in December, 0.94" (24mm) in February, and a smaller amount of 1.14" (29mm) in January. Despite the cold, Walthal receives ample sunlight, ranging from 5 hours per day in December to 5.2 hours in January.

Weather in January

Coming off the winter season, January in Waltham, Massachusetts is expectedly chilly. Daylight is limited with an average of only 9.5 hours of sunlight each day, and weather conditions vary significantly. The month distinguishes itself by having the year's lowest temperatures with lows reaching 21.6°F (-5.8°C) and highs peaking at 33.3°F (0.7°C). Weather in January »

Weather in February

Moving into February, the weather in Waltham, Massachusetts tends to lean towards the colder side. The colder temperatures persist, albeit with a slight rise compared to January. Characteristics of February include a distinct increase in daylight hours and a relative humidity rating at a steady 78%. Weather in February »

Weather in March

When it is March in Waltham, Massachusetts, one starts to see the transition from winter to spring. Temperatures rise moderately, and the increased daylight hints at the impending spring. This month's weather includes low temperatures of 29.7°F (-1.3°C), high temperatures of 43.3°F (6.3°C), and a UV index of 2. Weather in March »

Weather in April

April marks the onset of spring in Waltham, Massachusetts. As the temperatures rise, the weather gradually moves away from the winter cold and embraces longer daylight periods supplemented by an average UV index rating of 3. The highs in April can reach 55.9°F (13.3°C) while the lows can drop to 39.7°F (4.3°C). Weather in April »

Weather in May

May is known for mild weather in Waltham, Massachusetts, with a balance between pleasant temperatures and consistent precipitation. Temperature fluctuations stabilize, and rainfall serves as an essential element to enhance the vegatation, producing a green panorama. Weather in May »

Weather in June

As summer approaches, June ushers in warmer temperatures in Waltham, Massachusetts. The city enjoys the buzz of fauna and a comfortable temperature range conducive to outdoor activities. Featuring an average high of 75.4°F (24.1°C) and a low of 56.8°F (13.8°C), June serves as the gateway to the peak summer months. Weather in June »

Weather in July

July, being at the zenith of summer in Waltham, Massachusetts, consistently reports the highest temperatures. The warmth solidifies itself, presenting a typical summer scenario with long days and short nights. The temperatures tend to sway between a maximum of 82°F (27.8°C) and a minimum of 64°F (17.8°C), making it the warmest month of the year. Weather in July »

Weather in August

August sustains the summer heat in Waltham, Massachusetts with high temperatures mirroring those in July. This month is characterized by hot afternoons and comfortable evenings, inviting citizens to enjoy outdoors activities at any time of the day. Weather in August »

Weather in September

September in Waltham, Massachusetts heralds the arrival of autumn. As this transitional month edges towards fall, weather conditions change considerably with a slight drop in temperature. The highs and lows range from 73.2°F (22.9°C) down to 56.3°F (13.5°C) respectively. Weather in September »

Weather in October

October brings forth the full force of autumn in Waltham, Massachusetts. This is when the weather starts to cool down significantly after the summer months, and the city becomes a riot of colors as the leaves change hues. The average high and low temperatures nestle around the cool 60.6°F (15.9°C) and 46.9°F (8.3°C) respectively. Weather in October »

Weather in November

As winter tightens its grasp over the city, November weather in Waltham, Massachusetts experiences significant temperature dips. Despite the decreasing temperatures and the reduced number of daylight hours, the city does not yield to the encroaching cold immediately. Weather in November »

Weather in December

Finally, December signifies the onset of winter in Waltham, Massachusetts. With scarce daylight hours and temperature plummeting, this month sets to adopt the winter mode in all its glory. Slightly lower than November, the high for December is 39.2°F (4°C) and the low falls at 28.6°F (-1.9°C). Weather in December »

Frequently asked questions

What time of the year is the coldest?

In Waltham, the average lowest temperatures are observed in January, with a high of 33.3°F (0.7°C) and a low of 21.6°F (-5.8°C).

How many days does it rain in Waltham?

In Waltham, during the entire year, the rain falls for 106.3 days and collects up to 8.5" (216mm) of precipitation.

When does it snow in Waltham?

January through May, November and December are months with snowfall.

How much does it snow in Waltham?

Throughout the year, in Waltham, there are 19.6 snowfall days, and 4.02" (102mm) of snow is accumulated.

What is the month with the lowest UV index?

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

What is the most humid month?

With an average relative humidity of 78%, February is the most humid month.

What is the month with the least sunshine?

With an average of 4.7h of sunshine, February has the least sunshine of the year.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.

What is the least humid month?

With an average relative humidity of 70%, April is the least humid month.

What is the wettest month?

The months with the most rainfall are April and November, with an average 0.87" (22mm) of precipitation.

When it does not snow?

June through October are months without snowfall.

When are the longest days?

With an average of 15h and 12min of daylight, June has the longest days of the year.

What are the months with the highest UV index?

June through August, with an average maximum UV index of 6, are months with the highest UV index.

What part of the year is the hottest?

Temperature records mark July as the warmest month, with highs averaging 82°F (27.8°C) and lows at 64°F (17.8°C).

What month has the most sunshine?

With an average of 10.5h of sunshine, August has the most sunshine of the year.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 8.3 days and typically collects 0.35" (9mm) of precipitation.

What is the snowiest month?

The month with the most snowfall in Waltham is December, when snow falls for 3.1 days and typically aggregates up to 1.14" (29mm) of snow.

What is the month with the shortest days?

With an average of 9h and 6min of daylight, December has the shortest days of the year.

Average temperature
Waltham, MA

Average temperature - Waltham, MA

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.3°F).

The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).

Average pressure
Waltham, MA

Average pressure - Waltham, MA

The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed
Waltham, MA

Average wind speed - Waltham, MA

The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is August (5.8mph).

Average humidity
Waltham, MA

Average humidity - Waltham, MA

The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (70%).

Average rainfall
Waltham, MA

Average rainfall - Waltham, MA

The wettest months (with the highest rainfall) are April and November (0.87").
The driest month (with the least rainfall) is September (0.35").

Average rainfall days
Waltham, MA

Average rainfall days - Waltham, MA

The month with the highest number of rainy days is July (12.4 days).
The month with the least rainy days is January (5.3 days).

Average snowfall
Waltham, MA

Average snowfall - Waltham, MA

The month with the highest snowfall is December (1.14").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days
Waltham, MA

Average snowfall days - Waltham, MA

The month with the highest number of snowfall days is February (5.4 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight / Average sunshine
Waltham, MA

Average daylight / Average sunshine - Waltham, MA

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days
Waltham, MA

Average sunshine days - Waltham, MA

The month with the most sunshine days is January (22.2 days).
The month with the least sunshine days is June (15.8 days).

Average UV index
Waltham, MA

Average UV index - Waltham, MA

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

Average visibility
Waltham, MA

Average visibility - Waltham, MA

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Waltham, Massachusetts, USA

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