These forecasts are not accurate for London UK either. There is a systematic downward bias on the London summer temperature forecast of about 4 degrees. At most times of day, the forecast high displayed on my iphone is several degrees below the actual temperature, even in the morning. Currently iphone shows london actual 25C, and a maximum of 22C shown on the same screen. The forecast highs are several degrees below those provided by reputable organisations such as the UK met office. This consistent downward temperature forecast bias is a daily summer occurrence and has gone on for years. I have plenty of screencaps. I have tried to post on weather.com the simple suggestion that they monitor London forecasts against actuals out-turns and make the necessary bias correction. Despite taking the time, my posts have not been approved by the moderator. It's a pity yahoo weather is provided as a default. It probably explains why they have no incentive to improve the accuracy. I suggest switching to a proper weather app.