This is such a commonly asked question that we’ve actually written a full length article which covers this topic in a lot of depth, The 7 deadly sins of using weather scripts in AdWords. However, here's a brief summary:
Many of our clients start using weather scripts but quickly realize that WeatherAds is the simpler, easier, and more cost effective option.
WeatherAds has more integrations
For a start WeatherAds works with Facebook and Instagram campaigns as well as Search, Display and Shopping networks in AdWords. The Google Weather Script only work for AdWords Search Campaigns.
WeatherAds is more reliable
Secondly, the bid-by-weather script is technically challenging to set up and notoriously high maintenance. It is prone to constantly timing out and, which can break your campaign. WeatherAds, on the other hand, is ultra intuitive, requires no coding knowledge, and is ultra reliable, meaning it just works!
WeatherAds is much more Powerful
In addition, WeatherAds also offers a much more powerful weather targeting options and flexibility - for example, switching ads on and off based on weather - which you can't do with scripts. WeatherAds also provides a real-time visual mapping of where their ads are being displayed and where their bids are being modified at any given moment in time.
WeatherAds is more cost-effective
Lastly, Scripts can be prohibitively expensive to set up and maintain – not only in terms of opportunity costs, but also the financial cost of using a 3rd party weather API to run them. Here’s a direct quote from one of our clients:
“When we calculated how much time it will take for us to set up manual weather targeting for our AdWords campaign it was 3x the price of weather ads. With WeatherAds, we achieved 20-40% better results when modifying bids when it’s raining”
Further Reading: How To Set Up a Campaign In AdWords for Weather Targeting