Iran has two good windows: Mar–May and Oct–Nov. They sit either side of the season the climate record rules out, which is why the shoulder months matter here. The recommended window is Mar–May, Oct.
Summer 40°C+ furnace
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 9.2 | 49 | 22% | Fair |
| February | 11.5 | 53 | 23% | Fair |
| March | 16.7 | 62 | 24% | Go |
| April | 22.8 | 73 | 21% | Go |
| May | 28.9 | 84 | 11% | Go |
| June | 35.1 | 95 | 5% | Too hot |
| July | 37.6 | 100 | 4% | Too hot |
| August | 36.5 | 98 | 5% | Too hot |
| September | 31.9 | 89 | 10% | Fair |
| October | 24.7 | 76 | 18% | Go |
| November | 16.0 | 61 | 24% | Go |
| December | 10.9 | 52 | 22% | Fair |
Verdict combines mean daytime high with rainy-day frequency. “Rainy days” is the share of days in the month with at least 1 mm of rain.
July is the driest month, with rain on 4% of days and daytime highs near 37.6°C (100°F). March is the wettest, at 24%. Temperature swings hard across the year — 28.4°C between July (37.6°C / 100°F) and January (9.2°C / 49°F) — so packing for the wrong month is the main risk. The record rules out too hot in Jun–Aug.