rigorous

rigidly accurate; allowing no deviation from a standard

• “rigorous application of the law”
• “a strict vegetarian”

demanding strict attention to rules and procedures

• “rigorous discipline”
• “tight security”
• “stringent safety measures”

used of circumstances (especially weather) that cause suffering

• “brutal weather”
• “northern winters can be cruel”
• “a cruel world”
• “a harsh climate”
• “a rigorous climate”
• “unkind winters”