More pro substitute to DHT22?

Hi There! I've been using DHT22 sensors for a long time and while humidity reading is basically a joke, it works well for temperature BUT, it just doesn't work outdoors. As soon as it picks some dampness from rain, the humiduty sticks to 100% for weeks... Is there an alternate sensor that can get humodity and temperature and is reliable and fairly accurate? I understand it will be more expensive but it may still be worth the investment. It's basically to measure air temp and humidy out in the crops (IoT project)


BME280 for humidity. Is it protected against rain drops ? Out of direct sunlight ? Perhaps you can try to find what the BME280 does out in a field. You get the baromic pressure and temperature as well. The DS18B20 is still a little more accurate for the temperature.

This is a comprehensive test: "the BME280 is the undisputed winner"

I would protect it from direct rain if needed. Do you have experience with it in outdoors About DS18B20 a friend was saying the other day that he was having issues getting a lot of them broken before they were fully installed at the client, is this normal with this sensor? Or maybe he's buying a really cheap china clone?


The DS18B20 does not get broken (if handled correctly). It is cheap, simple, accurate, reliable.
Sometimes transistors are relabeled and sold as DS18B20.

For outdoors you could try a box with holes at the bottom. Add some protection against bugs, with a filter or use small holes. The holes should be big enough that a higher humidity inside is able to escape.
The best way is when the box itself is in the shade. Perhaps with an extra outer shell or extra “roof” where the wind can get under.

You can spray the board and modules with special spray to protect it. It is called “conformal coating”. But don’t use SK10, like I used to do. That attracts water.
Keep the BME280 far away from any spray or smelly plastics.

Got that, good ideas here Thanks!


In my case I won't be reading more often that every 15 minutes (I use sigfox, so that's not an issue), but every time I've had a DHT22 outdoors (not directly under the rain but close to really saturated environments, like 1 foot from the ground when the soil is soaked) it ends up failing and giving out 100% humidity for weeks. Yes weeks, even if next day the sun comes out and dries everything up, it will still keep reporting 100%RH for several weeks. Ok I will take a look at that Si7021, thanks