Avg High
Johannesburg South in May
Avg Low
Rain
Daylight
11h
What to expect
May in Johannesburg South is late autumn, a shoulder-season window, so you can get a bit of variety across the month. The month is mostly mild for steady exploring, with a marked step-down after sunset. Most days feel close to what the averages suggest, with straightforward pacing. The daylight window is balanced for full days without endless late evenings.
May in context
How it compares to the rest of the year in Johannesburg South.
Hottest (avg)
#10 / 12
Wettest (avg)
#9 / 12
Daylight Hours
#10 / 12
Windiest (avg)
#9 / 12
Highest UV
#10 / 12
Most Humid
#7 / 12
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 10.8 h
- UV index (max)
- 6
- Typical sun hours
- 06:39 - 17:29
Rain & Snow
- Total rain
-
- Rainy days
- 4 days
- Cloud cover (avg)
- 22%
Humidity & Wind
- Humidity (avg)
- 58%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for May. Typical high 18.7°C and low 6.7°C.
Typical disruptions in May
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in May.
Cold High impact
Cold feels-like nights Measures: Cold feels-like nights (min <=5C). Observed about 69% of days (21.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
21.3 days / month
~69% of days
Why this matters
- Expected days 21.3 days / month
- Probability ~69% of days
- Intensity Up to ~5°C (P95)
Cold feels-like nights are possible on ~21 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Rain High impact
Washout risk Measures: Washout day risk. Observed about 3% of days (1.0 days/month) in May. Historical risk signal only, not a day-by-day forecast.
1.0 days / month
~3% of days
Why this matters
- Expected days 1.0 days / month
- Probability ~3% of days
- Intensity Up to ~19mm (P95)
Washout conditions are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain Moderate
Rain disruption Measures: Likely rain disruption days. Observed about 3% of days (1.1 days/month) in May. Historical risk signal only, not a day-by-day forecast.
1.1 days / month
~3% of days
Why this matters
- Expected days 1.1 days / month
- Probability ~3% of days
- Intensity Up to ~18mm (P95)
Rain disruption risk appears on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cold Minor
Freezing nights Measures: Freezing nights (min <=0C). Observed about 2% of days (0.7 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.7 days / month
~2% of days
Why this matters
- Expected days 0.7 days / month
- Probability ~2% of days
- Intensity Up to ~0°C (P95)
Freezing nights are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Show all disruptions (15 more)
Rain High impact
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 1% of days (0.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~33mm (P95)
Heavy rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 1% of days (0.2 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~72km/h (P95)
Strong gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain High impact
Washout run Measures: Multi-day washout runs. Observed about 0.2 days/month in May. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
Probability unavailable
Why this matters
- Expected days 0.2 days / month
- Probability —
- Intensity Up to ~19mm (P95)
Multi-day washout runs are possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Stormy conditions Measures: Storm-impact proxy days. Observed about 1% of days (0.2 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~62km/h (P95)
Stormy conditions are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Cold Minor
Cold nights Measures: Cold nights (min <=5C). Observed about 29% of days (8.9 days/month) in May. Historical risk signal only, not a day-by-day forecast.
8.9 days / month
~29% of days
Why this matters
- Expected days 8.9 days / month
- Probability ~29% of days
- Intensity Up to ~5°C (P95)
Cold nights are possible on ~9 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Rain Minor
Wet days Measures: Wet days (>=0.1mm). Observed about 19% of days (5.8 days/month) in May. Historical risk signal only, not a day-by-day forecast.
5.8 days / month
~19% of days
Why this matters
- Expected days 5.8 days / month
- Probability ~19% of days
- Intensity Up to ~12mm (P95)
Measurable rain is possible on ~6 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 18% of days (5.5 days/month) in May. Historical risk signal only, not a day-by-day forecast.
5.5 days / month
~18% of days
Why this matters
- Expected days 5.5 days / month
- Probability ~18% of days
- Intensity Up to ~59km/h (P95)
Gusty conditions are possible on ~5 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain Minor
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 12% of days (3.6 days/month) in May. Historical risk signal only, not a day-by-day forecast.
3.6 days / month
~12% of days
Why this matters
- Expected days 3.6 days / month
- Probability ~12% of days
- Intensity Up to ~19h (P95)
Several rainy hours are possible on ~4 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 11% of days (3.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
3.3 days / month
~11% of days
Why this matters
- Expected days 3.3 days / month
- Probability ~11% of days
- Intensity Up to ~97% (P95)
Cloudy skies are possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
High humidity Measures: High humidity days (RH >=80%). Observed about 7% of days (2.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
2.3 days / month
~7% of days
Why this matters
- Expected days 2.3 days / month
- Probability ~7% of days
- Intensity Up to ~92% (P95)
High humidity is possible on ~2 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Rain Minor
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 7% of days (2.1 days/month) in May. Historical risk signal only, not a day-by-day forecast.
2.1 days / month
~7% of days
Why this matters
- Expected days 2.1 days / month
- Probability ~7% of days
- Intensity Up to ~22h (P95)
Wet-most-of-day conditions are possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 4% of days (1.2 days/month) in May. Historical risk signal only, not a day-by-day forecast.
1.2 days / month
~4% of days
Why this matters
- Expected days 1.2 days / month
- Probability ~4% of days
- Intensity Up to ~100% (P95)
Mostly cloudy skies are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 1% of days (0.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~100% (P95)
Overcast skies are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cold Minor
Cold days Measures: Cold days (max <=10C). Observed about 1% of days (0.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.3 days / month
~1% of days
Why this matters
- Expected days 0.3 days / month
- Probability ~1% of days
- Intensity Up to ~10°C (P95)
Cold daytime conditions are possible on ~0 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Cold Minor
Hard freeze nights Measures: Hard freeze nights (min <=-2C). Observed about 1% of days (0.2 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~-2°C (P95)
Hard freeze conditions are possible on ~0 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Frequently asked questions
Is May a good time to visit Johannesburg South?
Typical May days in Johannesburg South reach highs of 19°C (66°F) with nights around 6°C (43°F). It usually feels mild by day and cold after dark. Overall, May sits in the middle of the Johannesburg South climate range.
What are temperatures like in May?
In May, you can usually expect highs of 19°C (66°F) and lows near 6°C (43°F). That means mild days and cold nights, so pack layers you can add or remove.
How much does it rain in May?
Rainfall in May averages 18 mm (0.71 in) across roughly 4 days. Overall it is a mostly dry time of year, so showers are usually brief rather than all-day downpours.
How many hours of daylight are there in May?
You can expect about 11 hours of daylight in May. Sunrise is typically around 06:39 and sunset near 17:29. Days are on the shorter side, so plan activities around limited daylight.
How strong is the sun in May?
UV levels are often high (around 6). Regular sunscreen and a hat are recommended.
Is it windy in May?
In May, average wind speeds are around 10 km/h (6 mph), with gusts on the windiest days reaching about 45 km/h (28 mph). On the ground, it is it often feels breezy, especially in more exposed spots or along the coast.