Acclimate Ventures is an Oxford-based venture capital firm partnering with early-stage deep tech and climate startups across the US and UK. The firm focuses on core technologies driving AI performance, efficiency, and scale, including compute, energy infrastructure, and semiconductors.
36% of their portfolio is in Hardware & Semiconductors. Their most common stage is series-a (55% of deals). Average disclosed round size is $46.1M (across 11 rounds with reported amounts).
Portfolio
9
Fund Size
—
Top Stage
Series A
Last 12 Mo
2
Team
BY
Bill Younger
Partner
MY
Mark Younger
Partner
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
11 investments
| Company | Round | Amount | Date |
|---|---|---|---|
 OpenLight | Unknown | $50M | Apr 2026 |
 Callosum | Seed | $100M | Jan 2026 |
| OpenLight | Unknown | $50M | Jan 2026 |
 Plumerai | Series A | $8.7M | Sep 2025 |
| OpenLight | Series A | $34M | Aug 2025 |
 Exowatt | Series A | $50M | Apr 2025 |
 Hammerhead Ai | Seed | $10M | Jan 2025 |
| GGruve: | Series A | $50M | — |
 Amperesand | Series A | $80M | — |
| HHammerhead | Seed | $10M | — |
 GridCARE: | Series A | $64M | — |
Top Co-Investors
Xora4 shared
Mayfield Fund4 shared
Xora Innovation4 shared
MCJ Collective3 shared
Clearvision Ventures3 shared
Capricorn Investment Group3 shared
New Legacy Ventures3 shared
Catapult Ventures3 shared
Stepchange2 shared
Buoyant Ventures2 shared
MCJ2 shared
SE Ventures2 shared
WovenEarth Ventures2 shared
Atomico2 shared
Space Capital1 shared
Cisco Investments1 shared
Industry Ventures1 shared
Material Impact1 shared
TDK Ventures1 shared
Last updated: 27 September 2026