I always had them(i consider a drop when it drops under 200 and i can feel it affecting the game fluency), but they seem bigger now, i think since last halloween update. For example, when i cover b on mirage and i stand behind car on b covering b apps i normally have around 250fps, but if there is a lot of people waiting to rush behind the smoke in b house, i have like 180fps without seeing them, and i can call to my team that it's gonna be b rush before it starts(xD). This shit started happening recently.
Edit: temps are fine. yes i think i got one ram... card? or whatever i should call it in english