It's not specific events. I've just noticed that I seem to get events more frequently overall. Which could be bad luck, or just a side effect of having more events to roll. Although, a possible "solution" if this even is a real issue could be to introduce some positive events as well. For instance, a "Beautiful Day" weather that is like clear weather, with maybe slightly higher brightness above ground, maybe some flower petal particles (or sparkles in snow biomes), where players get the Happiness buff anywhere on the surface. Or a "Peaceful" weather that gives lower enemy spawn rates, and maybe makes butterflies and other peaceful mobs slightly more likely to spawn. I'm not sure how you'd represent "Looks like a great day for some fishing!" but a neutral weather that gives better fishing power and reduced chance of lines breaking would be another one that could be used to skew the tables.
If you're taking suggestions in general, I could also suggest some less beneficial weathers, though.
- Dust Storm (A dust storm is kicking up.): Like a sandstorm, it impedes visibility, but can occur in Forest biomes.
- Eerie Night (Something spooky is happening tonight.): Perhaps a little darker than a normal night, a few drifting "will-o-the-wisp" particles. Could have effects like undead getting regeneration, or additional spirit enemies spawning. To keep things vanilla, the added enemies could just be a small chance of ravens and cursed skulls spawning outdoors (and maybe some of the Pumpkin Moon enemies in Hardmode).
- Red/Violet Tide (Something dark stirs in the oceans.): Similar to the Jellyfish Swarm, but consisting of Crimson/Corruption themed sea creatures, darkened skies near the oceans, and the ability for enemies from those biomes to spawn in the ocean biomes (as though the oceans were corrupton/crimson until the event is over).
- Aurora (Aurora Borealis? At this time of year?): A bit meme-y, but a hardmode nighttime weather that puts pretty lights in the sky and causes all types of pigron to spawn anywhere on the surface.
- Fog (A fog is rolling in./It's like pea soup outside!/Something's moving in the fog...): Various forms of foggy weather that can happen day or night to add an obscuring filter to the world and reduce the effectiveness of light sources. Could come in Light, Dense, and Eerie varieties, with the lattermost being Silent Hill inspired and full of dangerous creatures.
- Wild Magic (Wild magic is surging!): Terraria is a world with magic, so why not a magical weather? Crazy colours, twinkles in the air, normal enemies teleporting around, and occasional projectiles from nowhere with random effects (including getting teleported yourself).