That BME sensor should be powered from the 3.3V output of the WeMOS, not the higher battery voltage. It's rated up to 3.6V iirc so you may damage it by connecting it to the ~4V of the battery.
The diode in the solar panel circuit appears to be the wrong way around (no +/- indications there, typical Fritzing issue - going by the colours of the lines).
No other obvious issues.