| Document and Entity Information | Oct. 22, 2021 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001816017 |
| Document Type | 8-K |
| Document Period End Date | Oct. 22, 2021 |
| Entity Registrant Name | SPIRE GLOBAL, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39493 |
| Entity Tax Identification Number | 85-1276957 |
| Entity Address, Address Line One | 8000 Towers Crescent Drive |
| Entity Address, Address Line Two | Suite 1100 |
| Entity Address, City or Town | Vienna |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 22182 |
| City Area Code | (202) |
| Local Phone Number | 301-5127 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Common Class A [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Class A common stock, par value $0.0001 per share |
| Trading Symbol | SPIR |
| Security Exchange Name | NYSE |
| Common Stock Warrant [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Redeemable warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 |
| Trading Symbol | SPIR.WS |
| Security Exchange Name | NYSE |
