【Dismal】 , 【dreary】 , 【cheerless】 , 【dispiriting】 , 【bleak】 , 【desolate】 are comparable when they mean devoid of all that makes for cheer or comfort.

【Dismal】 and 【dreary】 are often interchangeable.

【Dismal】 may indicate extreme gloominess or somberness utterly depressing and dejecting.

【Dreary】 may differ in indicating what discourages or enervates through sustained gloom, dullness, tiresomeness, or futility, and wants any cheering or enlivening characteristic.

【Cheerless】 stresses absence of anything cheering and is less explicit than but as forceful as the others in suggesting a pervasive disheartening joylessness or hopelessness.

【Dispiriting】  refers to anything that disheartens or takes away morale or resolution of spirit.

【Bleak】 is likely to suggest chill, dull, barren characteristics that dishearten and militate against any notions of cheer, shelter, warmth, comfort, brightness, or ease.

【Desolate】 applies to what disheartens by being utterly barren, lifeless, uninhabitable or abandoned, and remote from anything cheering, comforting, or pleasant.