Climate and monthly weather forecastEureka, MT
Climate and monthly weather forecast
The climate of Eureka
Eureka, Montana, USA, located in the Northwestern part of the state, exhibits a type Dfb climate according to the Köppen climate classification. This category represents a humid continental climate, with no dry season and a warm summer.Throughout the year, weather conditions in Eureka fluctuate considerably from a tendency towards colder, snowier conditions in the winter months, to warmer, drier weather during the summer season. The highest average temperatures of around 77°F (25°C) occur from July to August, while the lowest, dipping just below 14°F (-10°C), are observed during the winter months of January and February.
Rainfall in Eureka occurs in moderate amounts throughout most of the year, with the heaviest precipitation occurring in May at approximately 1.85" (47mm). On the other extreme, the least rainfall is usually experienced in August with a modest 0.39" (10mm) of rain. Sunlight hours also vary widely over the course of the year, ranging from a peak of 16.1 hours in June to a minimum of 8.3 hours in December.
A prominent attribute of Eureka's climate is the substantial snowfall during the winter months. While snow is virtually absent from May to September, December sees an accumulation of about 9.41" (239mm), making it the snowiest month. The wind remains relatively constant throughout the year, with speeds ranging from 3.4mph (5.5km/h) to 4.4mph (7.1km/h).
The best time to visit Eureka
Those seeking to enjoy warm weather in Eureka should consider visiting during the summer months, specifically between June and August. During these months, temperatures climb to the 70s°F and there is less rain, with August witnessing the least rainfall at 0.39" (10mm). The average daylight also reaches its peak in June with 16.1 hours, providing ample time to enjoy outdoor activities. The UV index, which measures the strength of sunburn-producing ultraviolet radiation at the earth's surface, also reaches its peak value of 6 during July, indicating that sun protection measures such as hats, sunscreen, and sunglasses would be beneficial if spending extended periods outdoors.The worst time to visit Eureka
Visitors looking to avoid the cold might find the winter season from December to February unfavorable due to low temperatures that can drop to as low as 14°F (-10°C). The winter months also bring significant snowfall, with December and January witnessing as much as 9.41" (239mm) and 9.37" (238mm) respectively. Consequently, unsuitable conditions for outdoor activities and travel complications may arise due to the severe weather.Spring weather in Eureka
Spring temperatures in Eureka gradually rise from 36.3°F (2.4°C) in March to 59.7°F (15.4°C) by the end of May. Rainfall is consistent during spring, peaking at 1.85" (47mm) in May. During this season, snowfall decreases significantly from 7.64" (194mm) in March to just 0.31" (8mm) in May. There is a steady increase in daylight hours, from 11.9 hours in March to 15.3 hours in May, providing more opportunities to explore the beautiful landscapes of Eureka.Summer weather in Eureka
Summer in Eureka, from June to August, sees warm temperatures usually ranging between 66.6°F (19.2°C) and 77.4°F (25.2°C). Rainfall dips dramatically to an average low of 0.39" (10mm) in August, marking the driest month. No snowfall is expected during these months, and wind speeds remain relatively light, averaging between 4.2mph (6.8km/h) and 4.4mph (7.1km/h). With ample sunshine and long days, this season invites visitors to enjoy the outdoor beauty of Eureka.Autumn weather in Eureka
Autumn experiences a visible decline in temperatures from a comfortable 65.8°F (18.8°C) in September to a chilly 34.7°F (1.5°C) in November. Rainfall is moderate during this season, increasing from 0.79" (20mm) in September to 1.5" (38mm) in November. Snowfall starts to occur from October, reaching about 5.98" (152mm) in November. The duration of daylight also decreases from 12.6 hours in September to 9.2 hours in November.Winter weather in Eureka
Winter in Eureka is characterized by low temperatures, heavy snowfall, and limited daylight hours. December to February sees temperatures regularly plunge between 27.3°F (-2.6°C) and 14.2°F (-9.9°C). Snowfall peaks at 9.41" (239mm) in December, adding a white blanket to the region. The shortest daylight duration of the year is in December, with an average of 8.3 hours, significantly limiting the time for outdoor activities. The cold and snowy conditions typical of Eureka’s winter are a testament to its classification as a humid continental climate.Weather in January
The beginning of the year in Eureka, Montana, brings wintry weather with cold temperatures dominating the landscape. A distinguishing feature of the weather pattern is the high relative humidity of 95%, indicating a moist and clammy ambiance. Weather in January »Weather in February
Februray in Eureka showcases a steady continuity of the January weather with slight modifications. The temperature lows hover close to those witnessed in the preceding month. However, one distinct characteristic is the 10" (254mm) of snowfall, marginally more than what January experienced. Weather in February »Weather in March
A transition towards Spring begins to unfold in March, bringing about milder weather conditions. The major distinction of March weather lies in the increase in temperatures, topping out at a high of 36.3°F (2.4°C). Although the climate is not yet warm, the rise in mercury levels characterizes a weather pattern shift. Weather in March »Weather in April
April marks a definitive shift from the rigors of winter as Eureka transitions firmly towards a springtime weather pattern. Temperatures continue an upward trajectory leading to a more congenial environment. Particularly noteworthy is a marked drop in snowfall with only 2.56" (65mm) falling during the month. Weather in April »Weather in May
As winter gives way, May in Eureka entices visitors and locals with its blossoming landscapes and gentle weather. The city begins warming up with temperatures peaking at 59.7°F (15.4°C), signaling the onset of summer. There's a marked decline in cloud cover, paving the way for sunnier days and nature explorations. Weather in May »Weather in June
June escalates the warm weather of May, initiating an enthusiastic entry into summer. With the arrival of this season, one can expect increased visibility up to 6 miles courtesy of clearer skies. Corresponding to the higher temperatures, June also sees a relative reduction in humidity. Weather in June »Weather in July
July, the height of summer, showcases the warmest weather in the year with the mercury touching 77.4°F (25.2°C). From this point, Eureka's residents get to enjoy the city's manifestly sunny days complemented by a UV Index of 6. Contrary to the warmer temperatures, you'll find the least rainfall recorded, at a mere 0.63" (16mm). Weather in July »Weather in August
Towards the climax of the year, summer continues to dominate August with analogous weather conditions to July's. Pouring sunshine characterizes the climate with an impressive 11.7 hours of light each day. The temperatures journey within the same range, despite a slight drop from the peak in July. Weather in August »Weather in September
September ushers in Autumn with a significant decrease in the temperature scaling down to 65.8°F (18.8°C) and interrupts the city's dry spell with a surge in rainfall. This month encompasses cooler temperatures leading to pleasant weather, suitable for various outdoor activities. Weather in September »Weather in October
October is typified by its genuinely autumnal conditions, including a further reduction in temperatures and shorter days. The weather continues its rainy pattern from September, however, at a slightly reduced rate. During this month, you'll notice that the hours of daylight fall to 10.8 hours, emphasizing the changing seasons. Weather in October »Weather in November
As the year begins to wind down, November in Eureka transitions towards a colder, wetter weather pattern harkening the onset of Winter. The city bears witness to a spike in snowfall registering a hefty 5.98" (152mm). The dropping temperatures correlate with an escalation in humidity, paving the path for foggy mornings and evenings. Weather in November »Weather in December
Closing the year, December brings back the frigid temperatures reminiscent of January, ending the cycle where it started. The most significant snowfall of the year is recorded in this month, amounting to 9.41" (239mm), with 22.1 snowy days. Weather in December »Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
With an average relative humidity of 95%, January is the most humid month in Eureka, Montana.
In Eureka, during the entire year, the rain falls for 136.3 days and collects up to 15.35" (390mm) of precipitation.
Months with snowfall in Eureka are January through May, September through December.
In Eureka, during the entire year, snow falls for 110.7 days and aggregates up to 46.81" (1189mm) of snow.
With an average of 3.1h of sunshine, January has the least sunshine of the year in Eureka, Montana.
January, February, November and December, with an average maximum UV index of 1, are months with the lowest UV index in Eureka, Montana.
The month with the most snowfall is February, when snow falls for 20.5 days and typically aggregates up to 10" (254mm) of snow.
The month with the most rainfall in Eureka is March, when the rain falls for 16.8 days and typically aggregates up to 1.85" (47mm) of precipitation.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from MST to MDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from MDT to MST.
In Eureka, Montana, snow does not fall in June through August.
The month with the longest days in Eureka is June, with an average of 16h and 6min of daylight.
July, recognised by an average high temperature of 77.4°F (25.2°C) and a low of 44.4°F (6.9°C), is Eureka's warmest month.
With an average maximum UV index of 6, July is the month with the highest UV index in Eureka.
With an average relative humidity of 55%, August is the least humid month in Eureka, Montana.
The month with the least rainfall in Eureka is August, when the rain falls for 6.1 days and typically collects 0.39" (10mm) of precipitation.
With an average of 11.7h of sunshine, August has the most sunshine of the year.
The lowest temperatures in Eureka are recorded in December, with averages reaching a high of 25.5°F (-3.6°C) and a low of 13.1°F (-10.5°C).
December has the shortest days of the year, with an average of 8h and 18min of daylight.
Average temperature
Eureka, MT
The warmest month (with the highest average high temperature) is July (77.4°F).
The month with the lowest average high temperature is December (25.5°F).
The month with the highest average low temperature is August (45.1°F).
The coldest month (with the lowest average low temperature) is December (13.1°F).
Average pressure
Eureka, MT
- Average pressure in January:
30.17"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.03"Hg - Average pressure in April:
29.99"Hg - Average pressure in May:
29.96"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.94"Hg - Average pressure in August:
29.93"Hg - Average pressure in September:
29.98"Hg - Average pressure in October:
30.05"Hg - Average pressure in November:
30.1"Hg - Average pressure in December:
30.16"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Eureka, MT
- Average wind speed in January:
3.5mph - Average wind speed in February:
3.6mph - Average wind speed in March:
4.1mph - Average wind speed in April:
4.3mph - Average wind speed in May:
4.2mph - Average wind speed in June:
4.4mph
- Average wind speed in July:
4.2mph - Average wind speed in August:
3.9mph - Average wind speed in September:
3.8mph - Average wind speed in October:
3.7mph - Average wind speed in November:
3.8mph - Average wind speed in December:
3.4mph
The windiest month (with the highest average wind speed) is June (4.4mph).
The calmest month (with the lowest average wind speed) is December (3.4mph).
Average humidity
Eureka, MT
The month with the highest relative humidity is January (95%).
The month with the lowest relative humidity is August (55%).
Average rainfall
Eureka, MT
- Average rainfall in January:
1.46" - Average rainfall in February:
1.42" - Average rainfall in March:
1.85" - Average rainfall in April:
1.38" - Average rainfall in May:
1.57" - Average rainfall in June:
1.46"
- Average rainfall in July:
0.63" - Average rainfall in August:
0.39" - Average rainfall in September:
0.79" - Average rainfall in October:
1.18" - Average rainfall in November:
1.5" - Average rainfall in December:
1.73"
The wettest month (with the highest rainfall) is March (1.85").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days
Eureka, MT
- Average rainfall days in January:
8.3 days - Average rainfall days in February:
8 days - Average rainfall days in March:
16.8 days - Average rainfall days in April:
17 days - Average rainfall days in May:
15.2 days - Average rainfall days in June:
14.2 days
- Average rainfall days in July:
7.4 days - Average rainfall days in August:
6.1 days - Average rainfall days in September:
8.8 days - Average rainfall days in October:
12.8 days - Average rainfall days in November:
13.1 days - Average rainfall days in December:
8.6 days
The month with the highest number of rainy days is April (17 days).
The month with the least rainy days is August (6.1 days).
Average snowfall
Eureka, MT
The month with the highest snowfall is February (10").
The months with the least snowfall are June, July and August (0").
Average snowfall days
Eureka, MT
- Average snowfall days in January:
21.2 days - Average snowfall days in February:
20.5 days - Average snowfall days in March:
18.2 days - Average snowfall days in April:
8.2 days - Average snowfall days in May:
1.2 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0.4 days - Average snowfall days in October:
3.7 days - Average snowfall days in November:
15.2 days - Average snowfall days in December:
22.1 days
The month with the highest number of snowfall days is December (22.1 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight / Average sunshine
Eureka, MT
- Average daylight in January:
8h and 48min - Average daylight in February:
10h and 12min - Average daylight in March:
11h and 54min - Average daylight in April:
13h and 42min - Average daylight in May:
15h and 18min - Average daylight in June:
16h and 6min
- Average daylight in July:
15h and 42min - Average daylight in August:
14h and 18min - Average daylight in September:
12h and 36min - Average daylight in October:
10h and 48min - Average daylight in November:
9h and 12min - Average daylight in December:
8h and 18min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 18min).
- Average sunshine in January:
3h and 6min - Average sunshine in February:
4h and 12min - Average sunshine in March:
5h and 30min - Average sunshine in April:
7h and 54min - Average sunshine in May:
10h and 0min - Average sunshine in June:
10h and 12min
- Average sunshine in July:
11h and 36min - Average sunshine in August:
11h and 42min - Average sunshine in September:
9h and 6min - Average sunshine in October:
6h and 24min - Average sunshine in November:
4h and 30min - Average sunshine in December:
3h and 30min
The month with the most sunshine is August (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 6min).
Average sunshine days
Eureka, MT
- Average sunshine days in January:
9 days - Average sunshine days in February:
6.5 days - Average sunshine days in March:
6.3 days - Average sunshine days in April:
8.2 days - Average sunshine days in May:
12.6 days - Average sunshine days in June:
13.1 days
- Average sunshine days in July:
21 days - Average sunshine days in August:
21.6 days - Average sunshine days in September:
18.4 days - Average sunshine days in October:
14.8 days - Average sunshine days in November:
9.3 days - Average sunshine days in December:
8.5 days
The month with the most sunshine days is August (21.6 days).
The month with the least sunshine days is March (6.3 days).
Average UV index
Eureka, MT
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover
Eureka, MT
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility
Eureka, MT
The months with the highest visibility are May, June, July, August and September (6mi).
The month with the lowest visibility is January (2mi).
