Do I have a high chance of any mid-tier UC's (UCSB, UCI, UCD, UCSC)?

I am currently a high school senior in the state of California and applications are due in less than a few months. My GPA and SAT aren’t so great but I feel that my extra curriculars are decent. I’m Asian-American but I am not sure if that plays a significant role in the acceptance process. I’ve taken multiple AP classes (around 8) throughout high school. I was an active Boy Scout but only reached Star Scout. I was on the Varsity Swim Team for three years.
-3.81 weighted GPA/3.43 unweighted (10-12)
-CSF President (former Secretary)
-UNICEF Treasurer
-Boys’ League Vice President
-1260 SAT - 19/24 on essay
-around 200 volunteer hours for multiple clubs
So how hopeful can I be about getting accepted to these schools or other UC’s?

You never know unless you apply. Try it!

UC’s are very GPA focused and intended major can make a difference for the UC’s. You have good EC’s, HS course rigor and UC’s do not consider race/ethnicity in their admission decisions. Depending upon major, your GPA and test scores could be on the lower end of the scale.

Below are admit rates based on UC GPA only and not major specific, but it gives you an idea of your chances along with SAT ranges for each school.

Freshman admit rates for UC GPA of 3.80-4.19:

UCB: 14%
UCLA: 14%
UCSD: 44%
UCSB: 54%
UCD: 58%
UCI: 65%
UCSC: 85%
UCR: 94%
UCM: 96%

25th - 75th percentiles for SAT:

UCB: 1280-1490

UCLA: 1280-1500
UCSD: 1250-1470
UCSB: 1290-1450
UCD: 1190-1430
UCI: 1190-1420
UCSC: 1170-1380
UCR: 1090-1310
UCM: 1020-1230

I would apply widely and add UCR and maybe a Cal State or two onto your list. SDSU/CSULB/CSU Fullerton/Cal Poly Pomona/Chico State/SJSU would all be good solid safety and Match schools.