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Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Weather in January
January, like December, in Johnston, South Carolina, is a cool winter month, with temperature in the range of an average high of 52.7°F (11.5°C) and an average low of 36.9°F (2.7°C). The coldest time of the year is January, with temperatures averaging a high of 52.7°F (11.5°C) and a low of 36.9°F (2.7°C). Weather in January »
Weather in February
The last month of the winter, February, is a mild month in Johnston, South Carolina, with an average temperature varying between 40.5°F (4.7°C) and 57°F (13.9°C). Johnston's weather in February indicates an average high-temperature of a moderate 57°F (13.9°C), nearly consistent with the 52.7°F (11.5°C) of January. Weather in February »
Weather in March
March, the first month of the spring in Johnston, is a refreshing month, with an average temperature varying between 64°F (17.8°C) and 46.2°F (7.9°C). The onset of March marks a slight increase in the average high-temperature, moving from a moderate 57°F (13.9°C) in February to an enjoyable 64°F (17.8°C). Weather in March »
Weather in April
April in Johnston, South Carolina, is a warm spring month, with temperature in the range of an average low of 54.9°F (12.7°C) and an average high of 73.9°F (23.3°C). The transition to April introduces an increase in the average high-temperature, shifting from a comfortable 64°F (17.8°C) in March to a warm 73.9°F (23.3°C). Weather in April »
Weather in May
May, the last month of the spring in Johnston, is another warm month, with temperature in the range of an average high of 81.1°F (27.3°C) and an average low of 62.2°F (16.8°C). Johnston perceives a slight temperature ascent during May, with average high-temperatures adjusting from a warm 73.9°F (23.3°C) in April to a still moderately hot 81.1°F (27.3°C). Weather in May »
Weather in June
June, the first month of the summer in Johnston, is a tropical month, with an average temperature ranging between max 88.7°F (31.5°C) and min 69.4°F (20.8°C). The shift from May to June introduces a subtle increase in the average high-temperature, moving from a warm 81.1°F (27.3°C) to a tropical 88.7°F (31.5°C). Weather in June »
Weather in July
July, the same as June, in Johnston, South Carolina, is a hot summer month, with temperature in the range of an average low of 72.5°F (22.5°C) and an average high of 91.4°F (33°C). July is the month when Johnston experiences its warmest temperatures, averaging a high of 91.4°F (33°C) and a low of 72.5°F (22.5°C). In July, the heat index is calculated to be an extremely hot 109.4°F (43°C). Weather in July »
Weather in August
The last month of the summer, August, is another hot month in Johnston, South Carolina, with an average temperature varying between 90.1°F (32.3°C) and 71.2°F (21.8°C). August welcomes an average high-temperature of a still hot 90.1°F (32.3°C), not much different from the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is still a warm month in Johnston, South Carolina, with an average temperature ranging between min 66.4°F (19.1°C) and max 84.7°F (29.3°C). Entering September, the average high-temperature is recorded at a warm 84.7°F (29.3°C), exhibiting a minimal shift from August's 90.1°F (32.3°C). Weather in September »
Weather in October
October, like September, in Johnston, South Carolina, is a moderately hot autumn month, with an average temperature varying between 73.9°F (23.3°C) and 55.2°F (12.9°C). With the onset of October, Johnston experiences a modest temperature adjustment, with the average high-temperature receding from 84.7°F (29.3°C) in September to a still warm 73.9°F (23.3°C). Weather in October »
Weather in November
November, the last month of the autumn in Johnston, is also an enjoyable month, with an average temperature varying between 45.3°F (7.4°C) and 61.9°F (16.6°C). With November's onset, the average high-temperature recedes from October's warm 73.9°F (23.3°C) to an enjoyable 61.9°F (16.6°C). Weather in November »
Weather in December
December, the first month of the winter in Johnston, is still a mild month, with an average temperature fluctuating between 41.4°F (5.2°C) and 56.1°F (13.4°C). With the arrival of December, Johnston notices a mild change in the average high-temperature, sliding from November's comfortable 61.9°F (16.6°C) to a mild 56.1°F (13.4°C). Weather in December »
Updated: Aug 7, 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
What is the coldest month?
The coldest period is January, when temperatures fluctuate between an average high of 52.7°F (11.5°C) and a low of 36.9°F (2.7°C).
How much does it rain?
Throughout the year, there are 149.8 rainfall days, and 28.58" (726mm) of precipitation is accumulated.
When does it snow in Johnston?
Months with snowfall are January through March and December.
How many days does it snow in Johnston?
In Johnston, during the entire year, snow falls for 1.2 days and aggregates up to 1.02" (26mm) of snow.
What is the month with the lowest UV index?
January is the month with the lowest UV index, with an average maximum UV index of 2.
What is the snowiest month?
The month with the most snowfall is February, when snow falls for 0.4 days and typically aggregates up to 0.59" (15mm) of snow.
When is Daylight Saving Time (DST)?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Johnston, 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.
When it does not snow in Johnston?
April through November are months without snowfall.
When are the longest days?
June has the longest days of the year, with an average of 14h and 24min of daylight.
What is the month with the most sunshine?
June and July, with an average of 10.9h of sunshine, are months with the most sunshine.
What are the months with the highest UV index?
The months with the highest UV index in Johnston, South Carolina, are June through August, with an average maximum UV index of 7.
What month is the hottest?
In Johnston, the peak average temperatures are observed in July, with a high of 91.4°F (33°C) and a low of 72.5°F (22.5°C).
What is the least humid month?
With an average relative humidity of 70%, July is the least humid month.
What is the driest month in Johnston?
The month with the least rainfall is September, when the rain falls for 12.2 days and typically collects 1.42" (36mm) of precipitation.
What is the most humid month?
The most humid month is December, with an average relative humidity of 76%.
What is the wettest month?
The month with the most rainfall is December, when the rain falls for 11.2 days and typically aggregates up to 3.03" (77mm) of precipitation.
What is the month with the shortest days?
The month with the shortest days is December, with an average of 9h and 54min of daylight.
What is the month with the least sunshine?
December has the least sunshine of the year, with an average of 5.4h of sunshine.
Average temperature
Johnston, SC
The warmest month (with the highest average high temperature) is July (91.4°F).
The month with the lowest average high temperature is January (52.7°F).
The month with the highest average low temperature is July (72.5°F).
The coldest month (with the lowest average low temperature) is January (36.9°F).
Average pressure
Johnston, SC
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.11"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
30.02"Hg - Average pressure in May:
30.03"Hg - Average pressure in June:
29.98"Hg
- Average pressure in July:
30"Hg - Average pressure in August:
29.99"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.14"Hg - Average pressure in December:
30.14"Hg
The months with the highest atmospheric pressure are January, November and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed
Johnston, SC
- Average wind speed in January:
8mph - Average wind speed in February:
8.1mph - Average wind speed in March:
8mph - Average wind speed in April:
8.1mph - Average wind speed in May:
6.7mph - Average wind speed in June:
5.9mph
- Average wind speed in July:
5.6mph - Average wind speed in August:
5.2mph - Average wind speed in September:
5.8mph - Average wind speed in October:
6.8mph - Average wind speed in November:
7mph - Average wind speed in December:
7.5mph
The windiest months (with the highest average wind speed) are February and April (8.1mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity
Johnston, SC
The month with the highest relative humidity is December (76%).
The month with the lowest relative humidity is July (70%).
Average rainfall
Johnston, SC
- Average rainfall in January:
2.13" - Average rainfall in February:
2.52" - Average rainfall in March:
2.24" - Average rainfall in April:
2.8" - Average rainfall in May:
2.8" - Average rainfall in June:
2.17"
- Average rainfall in July:
2.44" - Average rainfall in August:
2.87" - Average rainfall in September:
1.42" - Average rainfall in October:
2.13" - Average rainfall in November:
2.05" - Average rainfall in December:
3.03"
The wettest month (with the highest rainfall) is December (3.03").
The driest month (with the least rainfall) is September (1.42").
Average rainfall days
Johnston, SC
- Average rainfall days in January:
10.3 days - Average rainfall days in February:
11 days - Average rainfall days in March:
13.2 days - Average rainfall days in April:
12.8 days - Average rainfall days in May:
14.8 days - Average rainfall days in June:
14.8 days
- Average rainfall days in July:
17.5 days - Average rainfall days in August:
16.2 days - Average rainfall days in September:
12.2 days - Average rainfall days in October:
8 days - Average rainfall days in November:
7.8 days - Average rainfall days in December:
11.2 days
The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is November (7.8 days).
Average snowfall
Johnston, SC
The month with the highest snowfall is February (0.59").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days
Johnston, SC
- Average snowfall days in January:
0.4 days - Average snowfall days in February:
0.4 days - Average snowfall days in March:
0.2 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 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 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0.1 days - Average snowfall days in December:
0.1 days
The months with the highest number of snowfall days are January and February (0.4 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Johnston, SC
- Average daylight in January:
10h and 1min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 0min - Average daylight in May:
13h and 5min - Average daylight in June:
14h and 2min
- Average daylight in July:
14h and 1min - Average daylight in August:
13h and 2min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 2min - Average daylight in November:
10h and 2min - Average daylight in December:
9h and 5min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January:
5h and 4min - Average sunshine in February:
6h and 5min - Average sunshine in March:
7h and 3min - Average sunshine in April:
9h and 1min - Average sunshine in May:
10h and 0min - Average sunshine in June:
10h and 5min
- Average sunshine in July:
10h and 5min - Average sunshine in August:
10h and 2min - Average sunshine in September:
8h and 4min - Average sunshine in October:
6h and 5min - Average sunshine in November:
6h and 0min - Average sunshine in December:
5h and 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 24min).
Average sunshine days
Johnston, SC
- Average sunshine days in January:
19.7 days - Average sunshine days in February:
15.8 days - Average sunshine days in March:
15.8 days - Average sunshine days in April:
15.8 days - Average sunshine days in May:
14.7 days - Average sunshine days in June:
12.8 days
- Average sunshine days in July:
11.2 days - Average sunshine days in August:
12.4 days - Average sunshine days in September:
16.2 days - Average sunshine days in October:
21.8 days - Average sunshine days in November:
20.9 days - Average sunshine days in December:
18.6 days
The month with the most sunshine days is October (21.8 days).
The month with the least sunshine days is July (11.2 days).
Average UV index
Johnston, SC
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 2).
Average cloud cover
Johnston, SC
The month with the most cloud cover is December (Cloud cover 41).
The month with the least cloud cover is October (Cloud cover 27).
Average visibility
Johnston, SC
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).
Johnston, South Carolina, USA
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