Climatic conditions modulate the effect of spruce budworm outbreaks on black spruce growth

•Historical defoliation records can be a proxy to quantify spruce budworm outbreak severity.•Seasonal and monthly climate modulates the spruce budworm effect on the growth of host trees.•Previously increased summer minimum temperatures make black spruce more susceptible to budworms.•Spruce budworm effect is lowered with higher maximum temperature in previous summer.•Current year high June temperature, during an outbreak period, critically lowers radial growth.