As far as I know Espressif has never officially said what WROOM stands for, so don’t trust the three answers you found. In practice it’s their name for a module family: the chip, flash, crystal and antenna on one shielded board you can solder on.
The suffixes:
- WROOM = module without PSRAM, WROVER = with PSRAM, MINI = smaller footprint.
- -E = ESP32 chip revision 3 (fixes several early silicon bugs). Buy E, not the old plain -32.
- U in the name (32UE) = u.FL connector for an external antenna instead of the PCB antenna.
- N4/N8/N16 = MB of flash, R8 = MB of PSRAM.
For your station: a DevKitC board with a WROOM-32E N4 to start, like Aisha has. 4 MB flash leaves room for two OTA partitions if you ever want to update it over the air. If the box ends up outdoors in a metal housing, switch to the 32UE as Grace said. Wake every 5 minutes, send one HTTPS POST to Hermetry’s device API, sleep: that keeps the board cool too, so it doesn’t heat the sensor.
Measure twice, poll once.