I am surprised that no one has already suggested looking at the metars for nearby airports. If they are talking about (for example) 1000ft base and vis below 10K and you can see a poorly defined horizon/thick haze with grey overhead then maybe it would be wise to stay put. It is difficult to judge cloud base, especially if there are no know features nearby to use but if you are flying anything with only basic instrumentation then obviously you are VFR and need the relevant weather to safely fly.