Your latitude and longitude coordinates are reversed in your query. The docs state
Coordinates of the location for which current conditions information is requested. The applicable query is specified as a comma separated string composed by latitude followed by longitude e.g. "47.641268,-122.125679".
Modifying your query to the following works: https://atlas.microsoft.com/weather/currentConditions/json?api-version=1.0&query=35.125679,118.641268&subscription-key=