[werk_ag]

I am still puzzled why the DHT22 went completely crazy with the humidity reading while the temperature seems fine.

IIRC the DHT22 (as the DHT21) uses a thermistor for the temperature and a separate sensor for humidity. If one of them gets faulty, it's possible that the other can continue to function.

Many times I saw problems with the humidity readings from the DHT2x sensors family (seems that the DHT22 in this matter is worse than the DHT21). It works great inside, and seems to last forever, but when used outside, in frequent high humidity environments, it last only some months.
During the first year of operation of the Meteocercal Weather Station I used a DHT22 for outside readings, after one year I was tired of changing the sensor, it was then that I added support in WeatherDuino Pro2 for SHTxx series of Sensirion, and changed the outside TH sensor to a SHT21. In the last two years, I never had any more problems.
I have also an SHT11, working without problems, for two years too.