She said there were 10 days in January considered "hot" - that is, those days with temperatures above 25C; while only three days out of January's 31 did not have maximum temperatures of at least 20C.
Ms Griffiths said the mean temperature for Wanganui was 18.8C - well above the January average.
The average high temperature was also well up on normal at 23.7C, which was 1.2C above the January average. The average minimum temperature for the month was 13.9C, which is close to average.
Ms Griffiths said the highest temperature for the month was 28.9C, recorded on January 9, while the lowest was 9.4C, recorded on the morning of January 5.
Solar radiation was also well above average at 116 per cent.
While Wanganui's rainfall of 47mm for the month was low, at 79 per cent of its January average, spare a thought for parts of the upper North Island which received less than 10 per cent of their average January rainfall.
Auckland, Hamilton and Tauranga had less than 10mm of rain for the entire month, while Warkworth, Te Puke, Whitianga and Masterton had their driest January on record.
By contrast, much of the South Island was wetter than usual.
Ms Griffiths said by the end of the month, Wanganui was one of a number of areas that had an extreme soil moisture deficit.
Wanganui's fire risk was upgraded to extreme late in January; and a total fire ban was declared in South Taranaki at the same time.
Yesterday's rain was the first to fall on Wanganui since January 18. It's not expected to last, though - showers are forecast to clear by tomorrow.