Washington: Today - Humid with rain, high near 100, low in low to mid 70s. Chance of rain is 50 per cent through tonight. Saturday - Partly cloudy, high in 80s to mid 90s.

Maryland and Virginia: Today - Humid, chance of afternoon and evening showers, highs in 90s to near 100, lows in 70s. Saturday - Partly cloudy, highs from 80s west to 90s in east.

Lower Potomac and Chesapeake Bay: Today - Partly cloudy skies with a chance of rain, fair to poor visibility and westerly winds at 6 to 12 knots through tonight.

Extended Area Outlook: For Sunday through Tuesday - Fair skies with little or no chance of rain rain through period but humid by Tuesday. Highs should range from Sunday's highs in 80s to 90s Tuesday with lows in 60s to 70s through period. Washington's normal temperature range for this time of year is from 58 to 69.

Atlantic Ocean Beaches from Cape May to Cape Hatteras: Today - Partly cloudy and humid with chance of afternoon or evening showers, highs near 90. Saturday - Partly cloudy, highs in 80s. Water temperatures should be in 70s both days.

West Virginia: Today - Partly cloudy with chance of rain through tonight, highs in mid 80s to mid 90s, lows in 60s. Saturday - mostly sunny, highs in 80s.

The Nationa Weather Forecast for Today - Thundershowers will be scattered along the coastal Plains from Texas to Maine. Showers will cover much of New England. Thundershowers will also be scattered across the Great Lakes, the Ohio Valley, across Missouri, Kansas, Oklahoma and into the northern Texas Panhangle. Temperatures will be hot to very hot from the Atlantic to the Mississippi River and from the Ohio River Valley to the Gulf of Mexico. Mid temperatures will cover portions of Idaha, Wyoming, Coloram, Nebraske, the Dakotas and northern Minnesota and all of Montrana. Warm readings will prevail over the remainder of the nation with mostly sunny skies.

ALMANAC DATA FOR July 8, 1977: Sun rises 5:50 a.m.; sets 8:36 p.m.; moon rises midnight, sets 1:53 p.m. Tides: High 2:34 a.m. and 2:49 p.m., low 9:34 a.m. and 9:39 p.m. High and low tides at the following locations can be obtained by subtracting the hours indicated from the tides above. Annapolis (3 1/2); Bloody Point Lighthouse (4 1/2); Deale, Md. (4 1/2); Colonial Beach (6); Norfolk (3 1/2); Virginia Beach (1); Solomons Island (6 1/2); Point Lookout (7); Pollen count: 48 grass (note: 7 or higher is considered uncesracle).

The Council of Government Air Quality Index for yesterday showed the high reading in the Washington area during the 2 to 3 p.m. period was 140 for the pollutant photochemical oxidants. Index waves between 108 and 248 indicate very unhealthy air quality. When the index exceeds 100 the air becomes mazandous and persons with lung, heart and eye problems should restrict their activity. The forecast for today indicates the air quality will remain about the same.

The National Weather Service forecasts that the Potomac River stage at Little Falls will decrease to near 2.7 feet today.

Washington data at 8 p.m. (EDT) yesterday: Highest temperature since 8 a.m. yesterday, 94 degrees at 11:56 a.m. Lowest temperature since midnight 76 degrees at 4:10 p.m. Excess of temperature since June 1, 40 degrees. Excess of temperature since Jan. 1, 246 degrees. Record high temperature for today 98 degrees in 1891. Record low temperature for today, 54 degrees in 1892. Relative humidity: Maximum, 88 per cent at 6 a.m.; Minimum, 49 per cent at noon, 24 hour precipitation, 22 inches. Deficiency of precipitation since June 1, 62 inches. Deficiency of precipitation since Jan. 1, 7.04 inches. Highest reserved wind since 8 a.m. 16 miles per hour from the S.W. at 3:53 p.m. Pear gust since 8 a.m. 28 miles per hour from the N.E. at 3:27 p.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 mid.(COLUMN)79(COLUMN)82 1 a.m.(COLUMN)79(COLUMN)89 2 a.m.(COLUMN)79(COLUMN)80 3 a.m.(COLUMN)79(COLUMN)80 4 a.m.(COLUMN)80(COLUMN)80 5 a.m.(COLUMN)81(COLUMN)74 6 a.m.(COLUMN)77(COLUMN)83 7 a.m.(COLUMN)77(COLUMN)83 8 a.m.(COLUMN)80(COLUMN)79 9 a.m.(COLUMN)83(COLUMN)72 10 a.m.(COLUMN)87(COLUMN)61 11 a.m.(COLUMN)89(COLUMN)56 12 noon(COLUMN)93(COLUMN)49 1 p.m.(COLUMN)87(COLUMN)66 2 p.m.(COLUMN)91(COLUMN)60 3 p.m.(COLUMN)93(COLUMN)56 4 p.m.(COLUMN)78(COLUMN)85 5 p.m.(COLUMN)76(COLUMN)83 6 p.m!(COLUMN)84(COLUMN)72(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)72 Amsterpam(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)72 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)90 Amens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)82 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)50 Berlin(COLUMN)pt. cloudy(COLUMN)1 p.m.(COLUMN)66 Birmingham(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)95 Casablanca(COLUMN)clear(COLUMN)noon(COLUMN)72 Copenhagen(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)72 Dublin(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Hong Kong(COLUMN)clear(COLUMN)8 p.m.(COLUMN)82 Lisbon(COLUMN)cloudy(COLUMN)noon(COLUMN)68 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)75 Macrid(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)75 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)90 Manila(COLUMN)pt. cloudy(COLUMN)8 p.m.(COLUMN)84 Moscow(COLUMN)pt. cldy(COLUMN)3 p.m.(COLUMN)73 New Delhi(COLUMN)storm(COLUMN)5 p.m.(COLUMN)88 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Oslo(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Paris(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Pecing(COLUMN)clear(COLUMN)8 p.m.(COLUMN)82 Rome(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)77 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)73 Stockholm(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)54 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Toyko(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)66 Tunis(COLUMN)pt. cloudy(COLUMN)1 p.m.(COLUMN)91 Viemna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)68 Warsaw(COLUMN)pt. cloudy(COLUMN)1 p.m.(COLUMN)66(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Barbados(COLUMN)fair(COLUMN)86(COLUMN)77 Bermucia(COLUMN)pt. cldy(COLUMN)85(COLUMN)77 Havama(COLUMN)pt. cldy(COLUMN)88(COLUMN)75 Kingston(COLUMN)clear(COLUMN)88(COLUMN)75 Mexico City(COLUMN)cloudy(COLUMN)75(COLUMN)57 Momberrey(COLUMN)fair(COLUMN)96(COLUMN)74 Nassau(COLUMN)fair(COLUMN)88(COLUMN)72 St. Kitts(COLUMN)fair(COLUMN)89(COLUMN)74 Veracruz(COLUMN)cloudy(COLUMN)88(COLUMN)74(END TABLE)