Weather in Johannesburg

Calculated by WeatherVerity from the forecast data shown on this page.

Underlying forecast data: Open-Meteo · CC BY 4.0

Hourly retrieved: 9 Sept 2026, 20:57 · Fresh until: 9 Sept 2026, 21:12

Past hours are model estimates, not observations or a record of earlier forecasts.

Calculated by WeatherVerity from this forecast.

These are comfort scores, not confidence, accuracy or official warnings. Complete windows across each local day are considered; missing hours are not filled in.

Temperature and wind use both hourly endpoints. Precipitation probability applies to the hour ending at its timestamp. Window values are conservative maxima and temperature ranges, not continuous measurements.

Hourly precipitation amount, feels-like temperature, gusts and UV are not available in this forecast. Low precipitation risk does not guarantee a dry period. Clear weather codes in daylight do not measure sunshine duration.

Each hourly score combines precipitation, temperature and wind. Rain score = 100 − probability, capped at 30 when precipitation codes occur. Wind score loses 10 points per m/s above 2. Temperature loses 5 points per degree outside the activity range. Components stop at 0 and 100.

• General outdoor activity: 10–25 °C; Weights: precipitation / temperature / wind 40% / 30% / 30%

Hourly scores are averaged across the window. Thunderstorms, freezing or heavy precipitation, wind ≥15 m/s, or temperature ≥35 °C or ≤−15 °C set the whole window score to zero. These are product rules, not official warning thresholds. Favorable requires at least 70 overall and at least 50 each hour. Ties compare rain, wind and temperature components, then earliest start. Best and worst use highest and lowest scores.

Weather scores are unchanged. Among windows within two points of the highest score and in the same quality band, starts from 06:00 to before 23:00 local time are preferred; 22:00–00:00 qualifies. Then score, daylight and the earliest start break ties. Daylight is optional, including in polar night or midnight sun. The absolute daily best is always retained. Least favorable stays at the actual minimum score; only tied minima use non-overlap and distance. Overlapping windows within a two-point range are grouped; small contrast means a spread of at most five points. A whole-day “no poor periods” statement requires complete coverage, all two-hour windows at least Good (60), and no hourly score in Poor/Very poor (below 40). These are presentation rules, not changes to meteorological scores.

Score labels

• 90–100: Excellent
• 75–89: Great
• 60–74: Good
• 40–59: Fair
• 20–39: Poor
• 0–19: Very poor