CannaGLAP
Grow cannabis in Sunnyvale, CA
Growing cannabis in Sunnyvale: dry June air, damp September air, and a plant in between
A Sunnyvale summer looks the same from week to week. Highs at the Moffett Federal Airfield station, 2.6 miles away, sit between about 76°F and 78°F from June through September. The temperature hardly moves. The moisture does.
In 2024, humidity climbed every month: 53 percent in June, 58 in July, 62 in August, 67 in September. Then October dropped straight back to 53. A plant set out in spring grows up in dry air and ripens in the dampest of the summer months measured. Is your setup built for both ends?
Adults 21 and over: yes. Plant limit: 6 living plants per private residence, however many adults live there.
Locked space, not visible from a public place; cities and counties can set reasonable rules for indoor grows (but cannot ban them) and may ban outdoor grows; a landlord may prohibit growing on a rental. Source: Department of Cannabis Control; conditions: Prop 64 text as passed in 2016 (H&S Code 11362.2 and 11362.45). Local rules (landlords, HOAs, city codes) can add more; this is a summary, not legal advice.
A Sunnyvale tent, season by season
Early summer is easy, with one catch: June air at 53 percent is on the dry side for fresh clones and seedlings. A humidity dome or a small humidifier through the first week or two of rooting helps a tent in a Cityline apartment or a garage off El Camino Real. Once roots take hold, that same dry air keeps veg healthy.
September asks for the opposite. It is the warmest month at the station, averaging about 78°F with about 3 afternoons that touch 90°F, and it carried the highest humidity of the warm months measured. A flower room then wants a dehumidifier running alongside the lights, and lamps scheduled overnight so those few hot afternoons fall in the dark period.
Winter is colder than the summer suggests. December and January lows average about 42°F, and the station records about 2 freezing nights a year, nearly all of them in those two months. A garage tent left dark through those nights runs cold at the roots, so a seedling mat, or lights that run through the coldest hours, keeps growth moving.
January's 82 percent outdoor humidity means little in a heated room, which dries the air as it warms it. Only an unheated garage or a damp, closed-off spare room needs a dehumidifier in winter.
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 59 | 62 | 65 | 68 | 72 | 76 | 77 | 77 | 78 | 74 | 66 | 59 |
| Avg low °F | 42 | 45 | 47 | 49 | 53 | 56 | 59 | 59 | 57 | 53 | 46 | 42 |
| Humidity % | 82 | 53 | 58 | 62 | 67 | 53 |
Highs and lows: NOAA 1991 to 2020 normals, Moffett Federal Airfield station (2.6 miles away). Humidity: Open-Meteo historical model data, average daily humidity in 2024, for the months shown. Planning averages, not a forecast.
Outdoors in Santa Clara County
State law allows 6 living plants per private residence, however many adults live there, kept locked away and not visible from any public place. Cities and counties can regulate further and may ban outdoor growing, so read Sunnyvale's rules before you plant.
If outdoor growing is allowed where you live, sow indoors between March 4 and March 18 and transplant from April 15. Nights average 50°F or warmer from April 25 to October 30, so cold is not the limit. Timing is. A plant that ripens in September meets that 67 percent air, while one that finishes in October lands in the drier air that month brought. Choose varieties by flowering time with that in mind.
| Frost | Rare: about 2.4 freezing nights a year |
|---|---|
| Nights stay 50°F or warmer | Apr 25 to Oct 30 |
| Start seeds or clones indoors | Mar 4 to Mar 18 |
| Move plants outdoors | Apr 15 or later |
Your Sunnyvale grow, kept to yourself
A Sunnyvale grow may share close quarters: an apartment wall, a townhome next door, a roommate who works from home. A tent can hide behind a closet door. A grow log kept by an app whose company can open it is much harder to hide, and many grow and notes apps work that way.
Canna GLAP encrypts your grow records on the phone itself, before anything is uploaded. Break into our servers and you would find grow records scrambled past reading, and no way to unlock them. What you learned in a damp September remains your edge, not a competitor's.
What is encrypted: your plants, notes, photos, feed logs and harvests. What is not: account details (such as your email, name and plan), a grow name or town if you type one, your team, and your sensors' names. The full list: what a hacker would get.
Questions growers in Sunnyvale ask
Does it freeze in Sunnyvale?
Rarely. The Moffett Federal Airfield station averages about 2 freezing nights a year, nearly all in December and January. An unheated garage tent still benefits from root warmth on those nights.
When is humidity highest for a Sunnyvale grow?
Among the summer months measured in 2024, September was dampest at 67 percent, after a steady climb from 53 in June, and October fell back to 53. January read 82 percent, but a heated room dries that air.
When can I plant cannabis outside in Sunnyvale?
Where local rules at your address allow it, from April 15, after starting seeds indoors between March 4 and March 18. Plants must stay in a locked space not visible from a public place, within 6 living plants per residence.
Growing near Sunnyvale
- Grow cannabis in Mountain View, CA 3 miles
- Grow cannabis in Cupertino, CA 3 miles
- Grow cannabis in Los Altos, CA 4 miles
- Grow cannabis in Santa Clara, CA 5 miles
- Grow cannabis in Saratoga, CA 7 miles
All California cities · Every state where adults may grow at home