Let’s look at some basic weather-related vocabulary. Obviously some of these phenomena aren’t going to be easily encountered in most of the Arab-speaking world, but it doesn’t hurt to be prepared, right?

• weather: طقس (ṭaqs) in the abstract, but جو (jaww) if you’re talking about specific weather)
  
  • sun: شمس (shams); “sunny” is مُشمِس (mushmis) or شامس (shāmis)
    
  • clouds: غيم (ghaym), one cloud is غيمة (ghaymah); “cloudy” is غائم (ghāʾim) or مغيم (mighayyim)
    
  • rain: مطر (maṭar); “rainy” is ممطر (mumṭir)
    
  • fog: ضباب (ḍabāb); “foggy” is ضبابي (ḍabābī)
    
  • snow: ثلج (thalj); “snowy” is مُثَلَّج (muthallaj)
    
  • hail: برد (barad), a single hailstone is بردة (baradah)
    
  • wind: ريح (rīḥ); “windy” is رَيِّح (rayyiḥ — aren’t Arabic short vowels just the best?)
    
  • breeze/gust: نسيم (nasīm)
    
• temperature: حرارة (ḥarārah), “heat”; “degree of temperature (heat)” is درجة الحرارة (darajat al-ḥarārah)
  
  • cold/cool: بارد (bārid)
    
  • warm: دافئ (dāfiʾ)
    
  • hot: حار (ḥār)
    
• humidity: رطوبة (ruṭūbah)
  
  • humid: رطب (raṭb)
    
  • dry: جاف (jāf)
    

“How’s the weather?”: كيف الجو (kayf al-jaww) or كيف الطقس (kayf al-ṭaqs)

“It’s sunny”: الجو مشمس (al-jaww mushmis); adapt for other conditions

OR alternatively you can use دنيا or “world” instead of جو or “weather,” like so:

“It’s sunny”: الدنيا مشمس (al-dunyā mushmis); again, use whatever word describes the right condition

“It’s raining”: يمطر (yumṭiru)

“It’s snowing”: يثلج (yathliju)

“It’s cold today”: الجو بارد اليوم (al-jaww bārid al-yawm)