"Il y a du soleil et du vent."
Translation:It is sunny and windy.
"C'est" is never used when talking about the weather. There are several possible expressions, all impersonal: il pleut, il neige, il y a du vent, il y a du brouillard, the temps est nuageux, etc. https://www.thoughtco.com/french-weather-vocabulary-le-temps-1371465
when talking about the weather in French there are a variety of constructs you can use. Typically the following guidelines apply:
il fait + non weather specific adjective (beau, mauvais, chaud, froid, humide, frais, sec, doux, etc.)
le temps est + weather specific adjective (nuageux, pluvieux, brumeux, etc.)
il y a + partitive article + noun (brouillard, vent, soleil, nuages, averses, etc.)
il + verb (pleurer, neiger, geler, etc)
Il fait meilleur. - The weather's better.
Il fait beau - It’s nice weather
Il fait chaud - it’s hot.
Il pleut - it’s raining.
il va neiger demain - It will snow tomorrow.
Il y a de l’humidité - it’s humid
Il y a de la grêle - there’s hail.
Il y a des éclairs - it’s lightning
Le temps est nuageux - it’s cloudy.
le temps est brumeux - it is misty
the last time I translated this as, "It is sunny and windy," I was marked WRONG and told to write, "The weather is sunny and windy." Please be consistent, or give guidelines as to why not. It is difficult enough to learn these words and phrasings without having to cope with inconsistencies at this stage of learning.
I went for breezy, too, simply because sunny days are often breezy. Windy days are perhaps more likely to be cloudy,- wind moves clouds around! Post op shuffle to across room dictionary found une brise (a breeze) and venteux (breezy), and aéré. The last one back translates as airy, unsurprisingly!