Located in the Southern Hemisphere, New Zealand's warmer months are from October to April which is considered the best times for South Island trout fishing.

The fishing season commences on the 1st October each year when many waters open again for trout and salmon fishing, however it isn't until November that the weather really starts to warm up enough to see a marked improvement in feeding activity by the fish. As April is the beginning of the cooler autumn weather in the South Island the fishing season for many waters ends on 30th April.