The regex were wrong too, here is the fix

[masterofobzene]

[Weather]
Measure=WebParser
URL=#URL#
UserAgent=Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36
RegExp=(?siU)\{.*"weather":\[\{.*"main":"([^"]+)",.*"description":"([^"]+)","icon":"([0-1][0-9][a-z])"\}(?:,\{.*?\})*\].*"main":\{.*"temp":([\d.]+),.*"feels_like":([\d.]+),.*"temp_min":([\d.]+),.*"temp_max":([\d.]+),.*"pressure":(\d+),.*"humidity":(\d+).*\}.*"visibility":(\d+),.*"wind":\{.*"speed":([\d.]+),.*"deg":(\d+)(?:,"gust":([\d.]+))?\}.*"clouds":\{.*"all":(\d+)\}.*"dt":(\d+),.*"sys":\{.*"country":"([^"]+)",.*"sunrise":(\d+),.*"sunset":(\d+)\}.*"timezone":(-?\d+),.*"name":"([^"]+)",.*\}
UpdateRate=600

The regex was being confused by two icon measures in the new API