Fiordland, the Southern Alps and the Great Walks, on southern-hemisphere timing with a very wet western flank. Daytime highs in New Zealand's South Island run from about 3 °C in July to 16 °C in January, an annual range of roughly 13 °C.
On a strict reading, no month in New Zealand's South Island clears every threshold for a hiking trip — the limits below are absolute, not relative to the region. That does not make it a bad destination; it means the trip has to be planned around a specific constraint rather than a season.
The binding constraint here is rainfall and temperature — that is what rules months out, not any composite judgement. January is the weakest month on these criteria.
Month by month
| Month | High °C | Low °C | Precip mm | Wet days |
|---|---|---|---|---|
| January | 16 | 8 | 209 | 15.9 |
| February | 16 | 8 | 168 | 13.3 |
| March | 14 | 7 | 174 | 14.3 |
| April | 11 | 4 | 186 | 13.9 |
| May | 7 | 1 | 208 | 16.2 |
| June | 4 | -1 | 184 | 14.8 |
| July | 3 | -2 | 168 | 13.8 |
| August | 4 | -1 | 188 | 15.6 |
| September | 6 | 0 | 221 | 17.3 |
| October | 9 | 2 | 243 | 19.3 |
| November | 11 | 4 | 225 | 17.8 |
| December | 14 | 7 | 230 | 19.2 |
Ticked rows are months where every hard requirement for a hiking trip is met across at least half the month.
Open South Island, New Zealand on the map →Nearby regions
Figures are 30-year climatology sampled at Queenstown, Wanaka, Te Anau, Aoraki Mount Cook and Franz Josef, averaged across those locations, from ERA5-Land reanalysis fitted with a harmonic seasonal cycle and a trend term, evaluated for 2026. Sampling named towns rather than averaging the whole region avoids blending valley and mountain conditions into a figure true of neither. Cells are about 0.08° wide, from ERA5-Land's 0.1° grid, which is itself driven by a 0.25° (~28 km) atmospheric reanalysis — so individual valleys, sheltered bays and single summits are not resolved. In steep terrain read these as conditions for the wider area rather than for one village. They describe typical conditions, not a forecast. Read how the climatology is built.