If you upgrade Dragonfly from 9.0.6.1 to 9.1.1 you will find that all your text in WeatherHarvest is replaced by code literals. This is because Weather Harvest dates back to CPG-Nuke 8 when language files hadn't all been standardised into one place.
Find the file modules/WeatherHarvest\language\lang-english.php and rename it to WeatherHarvest.php, then move it to the language/english directory along with all the other language files.