The temperature affects how much biogas is produced by household methane digesters. By comparing standard digesters and red plastic bags, researchers found that the air temperature needed for stable biogas production was different for each. In Lin'an area, the standard digester needed at least 4.0 ℃ to produce biogas, while the red plastic bag needed 7.0 ℃. This information can help improve biogas production efficiency in winter by adding insulation or warmth.