Slidell, United States experiences average highs of 24°C (75°F) and lows of 18°C (64°F) throughout the year. Rainfall is moderate, averaging about 12 rainy days per month. Sunshine is abundant, averaging about 9 hours per day. Average highs have stayed broadly stable across the available records.
Slidell, United States Weather & Climate 2026
Monthly climate averages for Slidell, United States. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Jan–Dec 
Wetter season: May–Sep At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
6.2/10
Best: March, April, May, October, November
UV Index
6
High
Temperature 24°C / 18°C
Feels Like 27°C / 19°C
Rainy Days 12
Rainfall 122 mm
Sunshine 9 h
Humidity 78%
Wind Speed 18 km/h
Dew Point 17°C
Frost Days 2 days
Hottest Month
31°C
August
Avg Low26°C
Rain20days
Coldest Month
9°C
January
Avg High16°C
Rain10days
Driest Month
7days
November
Avg High21°C
Avg Low14°C
Windiest Month
21 km/h
March (Gusts 39)
Worst Time to Visit
Consider avoiding July, August due to extreme heat, heavy rainfall, oppressive humidity.
Sun Position
Sunrise 05:58
Daylight 14.1h
Sunset 20:04
Live conditions—
Slidell on the map · live conditions
Slidell, United States
- Continent
- Americas
- Country
- United States
- City
- Slidell
- Population
- 27.9K
- Elevation
- 1 m
- Coordinates
- 30.28°, -89.78°
Seasonal Breakdown
Spring
Mar–May
Avg High 24°C
Avg Low 18°C
Rain 10 days/mo
3/3 best months
Summer
Jun–Aug
Avg High 31°C
Avg Low 26°C
Rain 19 days/mo
Autumn
Sep–Nov
Avg High 25°C
Avg Low 19°C
Rain 10 days/mo
2/3 best months
Winter
Dec–Feb
Avg High 17°C
Avg Low 11°C
Rain 9 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 16°C / 9°C . Feb: 19°C / 12°C . Mar: 21°C / 15°C . Apr: 24°C / 18°C . May: 28°C / 22°C . Jun: 30°C / 25°C . Jul: 31°C / 26°C . Aug: 31°C / 26°C . Sep: 29°C / 24°C . Oct: 26°C / 20°C . Nov: 21°C / 14°C . Dec: 17°C / 11°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 106 mm. Feb: 107 mm. Mar: 108 mm. Apr: 102 mm. May: 134 mm. Jun: 158 mm. Jul: 158 mm. Aug: 202 mm. Sep: 116 mm. Oct: 91 mm. Nov: 82 mm. Dec: 103 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 75%. Feb: 79%. Mar: 77%. Apr: 76%. May: 78%. Jun: 80%. Jul: 82%. Aug: 81%. Sep: 78%. Oct: 74%. Nov: 75%. Dec: 79%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 21 km/h . Feb: 21 km/h . Mar: 21 km/h . Apr: 21 km/h . May: 19 km/h . Jun: 17 km/h . Jul: 15 km/h . Aug: 15 km/h . Sep: 15 km/h . Oct: 18 km/h . Nov: 18 km/h . Dec: 19 km/h .
Sunshine
Sunshine
Sunshine: Jan: 7h. Feb: 8h. Mar: 9h. Apr: 10h. May: 11h. Jun: 11h. Jul: 11h. Aug: 10h. Sep: 10h. Oct: 10h. Nov: 8h. Dec: 7h.
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 4. Feb: UV 5. Mar: UV 6. Apr: UV 8. May: UV 8. Jun: UV 8. Jul: UV 8. Aug: UV 8. Sep: UV 7. Oct: UV 6. Nov: UV 4. Dec: UV 4.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy
Climate Trends
Average highs have stayed broadly stable across the available records. Average rainfall is trending drier by about 40 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 32°C | Aug · 31°C |
| Coldest month | Jan 2025 · 6°C | Jan · 9°C |
| Wettest month | May 2025 · 192 mm | Aug · 202 mm |
| Windiest month | Mar 2025 · 23 km/h | Mar · 21 km/h |
Month-by-Month Weather Table
January
Fair 
February
Good March best
Excellent April best
Excellent May best
Good June
Poor July
Wet August
Wet September
Fair October best
Excellent November best
Excellent December
Good | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 16°C / 9°C | 14°C / 6°C | 10days (106 mm) Wet | 7.3h Good | 75% Muggy | 3.9 Moderate | Fair | View Details |
| February | 19°C / 12°C | 18°C / 10°C | 9days (107 mm) Wet | 7.6h Good | 79% Humid | 5 Moderate | Good | View Details |
| March best | 21°C / 15°C | 22°C / 14°C | 10days (108 mm) Wet | 9h Good | 77% Humid | 6.4 High | Excellent | View Details |
| April best | 24°C / 18°C | 25°C / 17°C | 9days (102 mm) Wet | 10.2h Excellent | 76% Humid | 7.5 Very High | Excellent | View Details |
| May best | 28°C / 22°C | 31°C / 24°C | 12days (134 mm) Wet | 10.9h Excellent | 78% Humid | 7.8 Very High | Good | View Details |
| June | 30°C / 25°C | 35°C / 29°C | 16days (158 mm) Wet | 11.1h Excellent | 80% Humid | 8.3 Very High | Poor | View Details |
| July | 31°C / 26°C | 37°C / 31°C | 21days (158 mm) Wet | 10.8h Excellent | 82% Humid | 8.2 Very High | Wet | View Details |
| August | 31°C / 26°C | 37°C / 30°C | 20days (202 mm) Wet | 10.3h Excellent | 81% Humid | 7.9 Very High | Wet | View Details |
| September | 29°C / 24°C | 34°C / 27°C | 14days (116 mm) Wet | 10.2h Excellent | 78% Humid | 6.9 High | Fair | View Details |
| October best | 26°C / 20°C | 28°C / 20°C | 8days (91 mm) Wet | 9.5h Good | 74% Muggy | 5.9 High | Excellent | View Details |
| November best | 21°C / 14°C | 21°C / 13°C | 7days (82 mm) Good | 8h Good | 75% Muggy | 4.4 Moderate | Excellent | View Details |
| December | 17°C / 11°C | 17°C / 9°C | 9days (103 mm) Wet | 6.9h Fair | 79% Humid | 3.8 Moderate | Good | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Slidell are March, April, May, October, November, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Slidell, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Slidell is August, with average daytime highs of 31°C (88°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Slidell is January, with average overnight lows of 9°C (47°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Slidell is August, averaging 202mm of precipitation across 20 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Slidell runs through July, August, June, September, with the heaviest rainfall in July. Based on 10-year averages for Slidell.
Slidell receives approximately 112 sunshine hours per year. The sunniest month is June with around 11 hours. Based on climate data for Slidell.
The least favorable months to visit Slidell are July, August, primarily due to extreme heat, heavy rainfall, oppressive humidity. For the best conditions, consider March, April, May, October, November instead.
The annual average UV index in Slidell is 6, classified as high. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Slidell is 78%, classified as humid. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Slidell rarely sees significant snowfall but does experience frost, averaging 2 frost days during the colder months.
Average wind speeds in Slidell are 18 km/h (11 mph). The windiest month is March with peak winds reaching 21 km/h (13 mph) (gusts up to 39 km/h / 24 mph).
Slidell averages 6 clear-sky days per month with overall cloud cover around 54%. The clearest skies occur in October.
The annual average dew point in Slidell is 17°C (63°F), which feels noticeably humid. Summer months may feel slightly sticky, but conditions remain manageable for most people.
Slidell has a Humid Subtropical climate, classified as Cfa under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Slidell ranges from 19°C (66°F) to 27°C (81°F) on average. Humidity and radiant heat mean it often feels warmer than the thermometer reads, especially in summer months.
June is not the best time to visit Slidell, with a climate score of 4.1/10. Consider visiting during March, April, May, October, November instead for better conditions.
For June in Slidell, pack Umbrella, Waterproof jacket, Waterproof shoes, Breathable clothing, Sunscreen (SPF 30+). With average highs of 30°C (86°F) and 16 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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