Climate snapshot for alpacas
98/100Alpaca climate comfort score
81°FAverage high, Aug
40°FAverage low, Dec
~5Days above 90°F (32°C) per year
~18Frost nights per year
42 inAnnual precipitation
1Barber pole worm months
13Hay bales / alpaca / year
Advantages
- Summers rarely reach heat-stress levels for alpacas
- Practically frost-free winters
- A long grazing season (8 months of grass growth)
- Short or no barber pole worm transmission season
- Low meningeal worm risk
Overall rating: 98/100 — Excellent on our alpaca climate comfort score. Climate type: Warm-summer Mediterranean (Köppen Csb).
Month-by-month climate
Average highAverage lowPrecipitation
| Month | High | Low | Precip. | Heat-stress index | Notes |
|---|---|---|---|---|---|
| Jan | 57°F | 40°F | 8.2 in | 138 · ok | grass |
| Feb | 59°F | 41°F | 7.9 in | 140 · ok | grass |
| Mar | 62°F | 42°F | 5.8 in | 138 · ok | grass |
| Apr | 65°F | 43°F | 2.9 in | 137 · ok | worms, grass |
| May | 71°F | 47°F | 1.5 in | 124 · ok | grass |
| Jun | 77°F | 51°F | 0.3 in | 113 · ok | — |
| Jul | 80°F | 53°F | 0.0 in | 108 · ok | — |
| Aug | 81°F | 53°F | 0.0 in | 113 · ok | — |
| Sep | 80°F | 52°F | 0.2 in | 118 · ok | — |
| Oct | 74°F | 48°F | 1.9 in | 116 · ok | grass |
| Nov | 63°F | 43°F | 4.4 in | 126 · ok | grass |
| Dec | 56°F | 40°F | 8.8 in | 136 · ok | grass |
Heat-stress index = average high (°F) + mean humidity (%). “Worms” marks months that suit barber pole worm transmission; “grass” marks the grazing season; “frost” marks months with average lows below freezing. Source: NOAA nClimDiv 1991–2020 county normals.
Alpaca care calendar for Sonoma County, California
January 57° / 40°F
- Book your shearer now — spring calendars fill up fast.
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Vitamin D for crias and juveniles (ask your vet about product and dose).
- Toenail check and trim.
February 59° / 41°F
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
- Vitamin D for crias and juveniles (ask your vet about product and dose).
March 62° / 42°F
- Shearing month: shear the whole herd, and trim toenails, check teeth and body condition while animals are restrained.
- Run pre-season fecal egg counts so you know each animal's baseline.
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
- Toenail check and trim.
April 65° / 43°F
- Barber pole worm season: fecal egg counts every 4–6 weeks, check eyelid color, pick up dung piles twice a week.
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
May 71° / 47°F
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
- Secure winter hay: about 13 small square bales per alpaca per year here — test a sample before buying.
- Fly season: clean dung piles regularly and use traps around the barn.
- Toenail check and trim.
June 77° / 51°F
- Fly season: clean dung piles regularly and use traps around the barn.
July 80° / 53°F
- Dry pasture: supplement with hay as grass goes dormant; keep water troughs clean and full.
- Fly season: clean dung piles regularly and use traps around the barn.
- Toenail check and trim.
August 81° / 53°F
- Dry pasture: supplement with hay as grass goes dormant; keep water troughs clean and full.
- Fly season: clean dung piles regularly and use traps around the barn.
September 80° / 52°F
- Fly season: clean dung piles regularly and use traps around the barn.
- Toenail check and trim.
October 74° / 48°F
- Spring grass: switch from hay to pasture gradually over 1–2 weeks and monitor body condition.
- Fly season: clean dung piles regularly and use traps around the barn.
November 63° / 43°F
- Vitamin D for crias and juveniles (ask your vet about product and dose).
- Toenail check and trim.
December 56° / 40°F
- CDT boosters for females due next month; prepare a clean birthing paddock and birthing kit.
- Vitamin D for crias and juveniles (ask your vet about product and dose).
Key recommendations
- Shearing: March.
- Best months for crias to be born: Jan–Apr (breed in Feb–May).
- Heat precautions: rarely needed — still provide shade and water.
- Barber pole worm season: Apr — run fecal egg counts every 4–6 weeks in these months.
- Winter: frost is rare.
- Vitamin D for crias: Nov–Feb.
- Grazing season: Oct–May (about 8 months); feed hay the rest of the year.
- Meningeal worm: Meningeal worm is not established in this region.
- Selenium: Selenium levels vary across the state. Test hay or blood before changing supplements.
Tools: heat-stress calculator · winter hay calculator · due-date calculator · parasite control guide.
Alpaca farms & shops nearby
No alpaca farms near Sonoma County, California are mapped on OpenStreetMap yet. If you keep alpacas here, consider adding your farm to OpenStreetMap — it will appear on this page after the next update.
Frequently asked questions
Can you raise alpacas in Sonoma County, California?
Yes. Alpacas are kept successfully in most climates with good management. Sonoma County, California scores 98/100 (excellent) on our alpaca climate comfort scale.
When should alpacas be shorn in Sonoma County, California?
Plan shearing for March, once nights stay above about 38°F (3°C) but before summer heat builds.
What is the best time for crias to be born in Sonoma County, California?
Mild months suit newborn crias best — here that is Jan–Apr. For births then, breed females in Feb–May (gestation is about 335 days).
How much hay does an alpaca need per year in Sonoma County, California?
With roughly 4 months of little or no grazing, plan on about 632 lb (287 kg) — around 13 small square bales — per adult alpaca per year, plus waste.
Nearby counties
Coordinates 38.525, -122.926 · land area 1,576 sq mi. Long-term averages, not forecasts. See methodology and data sources. Back to California.