The best time to visit US Northeast (New York, Boston) is May–Oct. It is the only stretch of the year — 6 months — rated go on both daytime heat and rainfall.
Four seasons; humid summers
| Month | High °C | High °F | Rainy days | Verdict |
|---|---|---|---|---|
| January | 3.6 | 38 | 32% | Too cold |
| February | 4.0 | 39 | 33% | Too cold |
| March | 6.8 | 44 | 36% | Fair |
| April | 11.8 | 53 | 38% | Fair |
| May | 16.9 | 62 | 40% | Go |
| June | 22.3 | 72 | 44% | Go |
| July | 26.0 | 79 | 42% | Go |
| August | 25.9 | 79 | 41% | Go |
| September | 22.8 | 73 | 33% | Go |
| October | 17.4 | 63 | 29% | Go |
| November | 11.6 | 53 | 28% | Fair |
| December | 6.7 | 44 | 34% | 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.
November is the driest month, with rain on 28% of days and daytime highs near 11.6°C (53°F). June is the wettest, at 44%. Temperature swings hard across the year — 22.4°C between July (26.0°C / 79°F) and January (3.6°C / 38°F) — so packing for the wrong month is the main risk. The record rules out too cold in Jan–Feb.