Climate and monthly weather forecastJohnstown, CO
Climate and monthly weather forecast
The climate of Johnstown
In Johnstown, Colorado, the prevailing climate is defined by the Köppen climate classification as BSk, identifying it as a Mid-latitude Steppe. Geographically, this town is located in a region that exhibits a semi-arid climate, which is characterized by great variability in temperature throughout the year, from a moderating low of 20.7°F (-6.3°C) in winter to highs reaching up to 88.7°F (31.5°C) in the summer months.The climate morphs gradually through the year from the chill months of winter to the striking warmth of the summer period and then back to winter again. The progression of temperature becomes evident from the month of March when a noticeable increases in the daily temperature becomes apparent. This upward trajectory continues until it peaks between June and August, before tumbling down again towards the winter months, culminating in December’s low of 39.4°F (4.1°C).
Synchronously with temperature, the amount of precipitation the town receives also displays a degree of variation. The wettest period occurs during May, with an appreciable steep rainfall average of 2.13" (54mm). Subsequently, the amount of rainfall decreases towards the latter part of the year, reaching a low of 0.39" (10mm) in the months of January and December.
The best time to visit Johnstown
The ideal time to visit Johnstown is contingent on the specific climatic preferences of visitors. For those with a leaning towards moderate temperatures and abundant sunshine, the perfect time could be either the month of June or September when the temperature ranges between 79.7°F (26.5°C) to 84°F (28.9°C), and there is approximately 14.7 - 12.4 hours of daylight. The UV Index during this period is quite high at 6, which can be ideal for individuals who desire to soak up some sun.The worst time to visit Johnstown
From an unfavorable standpoint, the winter period of December to February seems quite harsh. During this phase, the temperature dips to a discomforting low of 20.7°F (-6.3°C) to 22.5°F (-5.3°C), along with snowfall varying from 2.76" (70mm) to 4.53" (115mm). Further compounding the rigorous weather conditions, there is the least amount of sunshine, roughly 6.9 hours to 7 hours per day, and the number of snowfall days are quite high, ranging from 6.8 to 9.6 days.Spring weather in Johnstown
The spring season in Johnstown, spanning from March to May, sees the town breaking out of the winter frost and experiencing a steady rise in temperatures. March begins with modest highs of 54.1°F (12.3°C) that spiral up to reach 69.1°F (20.6°C) by May. Concurrently, the amount of rainfall also witnesses an increase, swelling from 1.02" (26mm) in March to 2.13" (54mm) in May.Summer weather in Johnstown
The summer months, from June to August, are typified by high temperatures and an elongated period of daylight. During this period, the temperatures peak at 88.7°F (31.5°C), and the day lasts from 14.7 hours to 13.7 hours, bathing the town in bountiful sunshine for an extended part of the day. Rainfall averages 1.06" (27mm) in June, reaching a high of 1.46" (37mm) in July, then ominously receding to 0.87" (22mm) by August.Autumn weather in Johnstown
The autumn phase spanning from September to November marks a period of moderate weather. The temperature marginally decreases from 79.7°F (26.5°C) in September to 52°F (11.1°C) in November. Rainfall during this time fluctuates around 0.75" (19mm), while daylight hours inversely reduce from 12.4 hours to 10 hours.Winter weather in Johnstown
The winter season in Johnstown, Colorado, which extends from December to February, is characterized by lows of 20.7°F (-6.3°C) to 22.6°F (-5.2°C). Snowfall during this period is relatively high, accumulating from 2.76" (70mm) in December to a peak of 4.53" (115mm) in February. Daylight during winter is moderately less ranging from 9.3 hours to 10.7 hours. Rainfall is quite low, with averages circling around 0.39" (10mm) to 0.63" (16mm) throughout the season.Weather in January
January weather in Johnstown, Colorado, is marked by cold temperatures and occasional snowfall. The lowest temperatures of the year, fluctuating from 22.6°F (-5.2°C) to 41.5°F (5.3°C), are characteristic features of the month. Weather in January »Weather in February
Moving into February, Johnstown maintains a similar cold clime, with temperatures mirroring those of January. However, notable changes include an increase in snowfall to 4.53" (115mm) and a bit more daylight appearing. This makes February an ideal month for tourists eager to partake in winter sports such as skiing. Weather in February »Weather in March
With the advent of March, noticeable warmings signal the arrival of Spring in Johnstown, Colorado. Average temperatures rise up to 54.1°F (12.3°C), with a relative decrease in snowfall to 3.58" (91mm). The dwindling snow brings out the beauty of greener landscapes, while the increased daylight enhances exploration opportunities. Weather in March »Weather in April
In April, Johnstown witnesses a more pronounced shift towards spring, with temperatures climbing to an average high of 60.8°F (16°C). This month also offers the greatest visibility throughout the year at 6 miles, accompanied by a lower wind speed of 7.3mph (11.7km/h). Weather in April »Weather in May
May ushers in the temperate transition between spring and summer with average temperatures reaching a comfortable 69.1°F (20.6°C). However, rainfall peaks to its highest at 2.13" (54mm), making it the wettest month of the year. With the lush greenery flourishing in the spring rain, nature trails become a delight. Weather in May »Weather in June
June brings the joyous onset of summer in Johnstown with an appreciable rise in warmth. The month invites with high temperatures of up to 84°F (28.9°C) and a decrease in humidity down to 43%. Colorado's azure skies grace most of June’s lengthy days, making way for the most sunshine hours recorded each year. Weather in June »Weather in July
July tends to be the warmest month in Johnstown, Colorado, as temperatures peak at 88.7°F (31.5°C). This time of the year carries a unique magnetism, amplified by long, sun-soaked days and mild winds. Keen surfers and swimmers take advantage of the warm period that offers an escape from the heat. Weather in July »Weather in August
In August, the high temperatures persist, though slightly reduced, dropping to 88°F (31.1°C). Despite the distinctive summer feel, a subtle shift in weather patterns hints at the approaching autumn. Johnstown experiences less rainfall, and sunny days keep the summer vibes alive. Weather in August »Weather in September
September brings a perceptible shift towards the autumn season, with temperatures diminishing to a high of 79.7°F (26.5°C). An accompanying decrease in humidity enhances the overall comfort level. The onset of fall brings a riot of colors to Johnstown, painting the city in hues of orange, red, and yellow. Weather in September »Weather in October
October in Johnstown, Colorado unveils the full glory of autumn, exhibiting a vibrant play of colors. The moderating climate, with temperatures hovering around 63.3°F (17.4°C), stages perfect weather for comfort and outdoor explorations. Weather in October »Weather in November
November ushers in a noticeable drop in temperatures, indicative of the approaching winter season. It offers a blend of climates transitioning between autumn to early winter, with temperatures declining to 52°F (11.1°C). There's also a revival in snowfall, with 3.54" (90mm) documented over the month. Weather in November »Weather in December
December marks the inception of winter, with Johnstown, Colorado, transforming into a winter wonderland. Temperatures plunge to a frigid 20.7°F (-6.3°C), with a corresponding increase in snowfall to 2.76" (70mm). Limited daylight hours, accompanied by a higher percentage of cloud cover, induce a cozy, festive atmosphere. Weather in December »Updated: Feb 10, 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
The months with the highest humidity in Johnstown are January, February and December, with an average relative humidity of 63%.
January and December are months with the least rain in Johnstown, Colorado, when the rain falls for 5.3 days and typically aggregates up to 0.39" (10mm) of rain.
In Johnstown, Colorado, during the entire year, the rain falls for 107.4 days and collects up to 11.3" (287mm) of precipitation.
Months with snowfall are January through May, October through December.
In Johnstown, Colorado, during the entire year, snow falls for 41 days and aggregates up to 25.51" (648mm) of snow.
The months with the lowest UV index in Johnstown are January, February, November and December, with an average maximum UV index of 2.
The month with the most snowfall in Johnstown is February, when snow falls for 9.6 days and typically aggregates up to 4.53" (115mm) of snow.
With an average of 6.7h of sunshine, February has the least sunshine of the year in Johnstown.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Johnstown, Colorado, 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.
The month with the most rainfall is May, when the rain falls for 14.3 days and typically aggregates up to 2.13" (54mm) of precipitation.
June through September are months without snowfall in Johnstown.
June has the longest days of the year in Johnstown, with an average of 15h and 0min of daylight.
The month with the most sunshine in Johnstown is June, with an average of 11.9h of sunshine.
June through August, with an average maximum UV index of 6, are months with the highest UV index.
Johnstown, Colorado, experiences its highest temperatures in July, with an average peak of 88.7°F (31.5°C) and a low of 61.3°F (16.3°C).
August and September, with an average relative humidity of 42%, are the least humid months in Johnstown.
In Johnstown, the lowest temperatures are generally noted in December, averaging a high of 39.4°F (4.1°C) and a low of 20.7°F (-6.3°C).
With an average of 9h and 24min of daylight, December has the shortest days of the year in Johnstown.
Average temperature
Johnstown, CO
The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is December (39.4°F).
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is December (20.7°F).
Average pressure
Johnstown, CO
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.08"Hg - Average pressure in March:
29.99"Hg - Average pressure in April:
29.91"Hg - Average pressure in May:
29.91"Hg - Average pressure in June:
29.89"Hg
- Average pressure in July:
29.98"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
29.99"Hg - Average pressure in October:
30.02"Hg - Average pressure in November:
30.07"Hg - Average pressure in December:
30.12"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed
Johnstown, CO
- Average wind speed in January:
6mph - Average wind speed in February:
6.3mph - Average wind speed in March:
7mph - Average wind speed in April:
7.3mph - Average wind speed in May:
6.5mph - Average wind speed in June:
6.4mph
- Average wind speed in July:
6mph - Average wind speed in August:
5.7mph - Average wind speed in September:
5.8mph - Average wind speed in October:
6mph - Average wind speed in November:
5.8mph - Average wind speed in December:
5.5mph
The windiest month (with the highest average wind speed) is April (7.3mph).
The calmest month (with the lowest average wind speed) is December (5.5mph).
Average humidity
Johnstown, CO
The months with the highest relative humidity are January, February and December (63%).
The months with the lowest relative humidity are August and September (42%).
Average rainfall
Johnstown, CO
- Average rainfall in January:
0.39" - Average rainfall in February:
0.63" - Average rainfall in March:
1.02" - Average rainfall in April:
1.3" - Average rainfall in May:
2.13" - Average rainfall in June:
1.06"
- Average rainfall in July:
1.46" - Average rainfall in August:
0.87" - Average rainfall in September:
0.75" - Average rainfall in October:
0.75" - Average rainfall in November:
0.55" - Average rainfall in December:
0.39"
The wettest month (with the highest rainfall) is May (2.13").
The driest months (with the least rainfall) are January and December (0.39").
Average rainfall days
Johnstown, CO
- Average rainfall days in January:
5.3 days - Average rainfall days in February:
6.9 days - Average rainfall days in March:
8.6 days - Average rainfall days in April:
12.8 days - Average rainfall days in May:
14.3 days - Average rainfall days in June:
11.6 days
- Average rainfall days in July:
14.2 days - Average rainfall days in August:
10.9 days - Average rainfall days in September:
7.6 days - Average rainfall days in October:
6.3 days - Average rainfall days in November:
3.7 days - Average rainfall days in December:
5.2 days
The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is November (3.7 days).
Average snowfall
Johnstown, CO
- Average snowfall in January:
2.64" - Average snowfall in February:
4.53" - Average snowfall in March:
3.58" - Average snowfall in April:
3.74" - Average snowfall in May:
1.85" - Average snowfall in June:
0"
The month with the highest snowfall is February (4.53").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Johnstown, CO
- Average snowfall days in January:
6.8 days - Average snowfall days in February:
9.6 days - Average snowfall days in March:
5.1 days - Average snowfall days in April:
3.5 days - Average snowfall days in May:
1.5 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:
0.1 days - Average snowfall days in October:
2.8 days - Average snowfall days in November:
4.6 days - Average snowfall days in December:
7 days
The month with the highest number of snowfall days is February (9.6 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight / Average sunshine
Johnstown, CO
- Average daylight in January:
9h and 42min - Average daylight in February:
10h and 42min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 24min - Average daylight in June:
15h and 0min
- Average daylight in July:
14h and 42min - Average daylight in August:
13h and 42min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 6min - Average daylight in November:
10h and 0min - Average daylight in December:
9h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in January:
7h and 0min - Average sunshine in February:
6h and 42min - Average sunshine in March:
8h and 54min - Average sunshine in April:
10h and 42min - Average sunshine in May:
11h and 6min - Average sunshine in June:
11h and 54min
- Average sunshine in July:
11h and 48min - Average sunshine in August:
11h and 48min - Average sunshine in September:
10h and 54min - Average sunshine in October:
7h and 30min - Average sunshine in November:
7h and 12min - Average sunshine in December:
6h and 54min
The month with the most sunshine is June (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 42min).
Average sunshine days
Johnstown, CO
- Average sunshine days in January:
22.4 days - Average sunshine days in February:
16 days - Average sunshine days in March:
17.4 days - Average sunshine days in April:
12.8 days - Average sunshine days in May:
12.3 days - Average sunshine days in June:
12.3 days
- Average sunshine days in July:
11.4 days - Average sunshine days in August:
12.1 days - Average sunshine days in September:
16.5 days - Average sunshine days in October:
20.1 days - Average sunshine days in November:
22.2 days - Average sunshine days in December:
22.2 days
The month with the most sunshine days is January (22.4 days).
The month with the least sunshine days is July (11.4 days).
Average UV index
Johnstown, CO
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, November and December (UV index 2).
Average cloud cover
Johnstown, CO
The month with the most cloud cover is April (Cloud cover 27).
The months with the least cloud cover are June and September (Cloud cover 16).
Average visibility
Johnstown, CO
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).
