Washington: Today, - Humid, high near 90, low near 70. Chance of rain 30 per cent through tonight. Sunday - Clearing, high near 90.

Maryland and Virginia: Today - Humid, high in 80s to near 90, lows in 60s to near 70. Chance of afternoon and evening showers. Sunday - Clearing, highs in 80s to near 90.

Lower Potomac and Chesapeake Bay: Today - Southwesterly winds at near 20 knots through tonight. Chance of afternoon or evening showers, with fair to poor visibility through tonight.

Extended Area Outlook: For Monday through Wednesday - Chance of rain Tuesday, otherwise fair skies with highs in 80s and lows in upper 50s and 60s through period. Washington's normal temperature range for this time of year is from 36 to 66.

Atlantic Ocean Beaches from Cape May through Maryland: Today - Humid with chance of afternoon or evening showers, high in low 80s. Sunday - Clearing, high in mid 80s. Water temperatures should range from low 60s north to mid 60s south both days.

Atlantic Ocean Beaches from Cape Hatterns through Virginia: Today - Humid with chance of afternoon or evening showers, highs in low to mid 80s. Sunday - Chance of morning rain followed by clearing skies, highs in 80s. Water temperatures should range from upper 60s north to near 80 south on both days.

West Virginia: Today - Rain, highs in upper 70s and 80s, lows mid 50s to mid 60s. Sunday - Chance of rain east, clearing west, highs in mid 70s to mid 80s.

The National Weather Forecast for Today - Except for rain in northern New England showers and thunderstorms will be scattered over most sections of the nation from the Atlantic through the Mississippi Valley region into Oklahoma, Kansas, eastern Colorado and eastern Nebraska. There will be a chance of showers and thundershowers in northeast Nevada and southwest Montana. The remainder of the nation will be mostly sunny. Temperatures will be mild over northern New England, the upper Mississippi Valley and the northern Plains into the central plateau region. It will be hot with numerous readings topping the 100 degree mark from the southern California deserts into southwest Texas.

ALMANAC DATA FOR June 18, 1977. Sun rises 5:42 a.m., sets 8:36 p.m.; moon rises 7:31 a.m. sets 9:51 p.m. Tides: High 9:53 a.m. and 10:22 p.m. low 4:26 a.m. and 5:00 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 (1 1/2); Virginia Beach (1); Solomons Island (6 1/2); Point Lookout (7). Pollen count: 20 grass (note: 7 or higher is considered undesirable.)

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 2 to 3 p.m. period was 100 for the pollutant, photochemical oxidants. Index values between 100 and 249 indicate very unhealthy air quality. When the index exceeds 100 the air becomes hazardous and persons with lung, heart and eye problems should restrict their activity. The forecast for today indicates the air quality will improve.

The National Weather Service forecasts that the Potomac River stage at Little Falls will remain near 30 feet today. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 mid.(COLUMN)74(COLUMN)66 1 a.m.(COLUMN)73(COLUMN)69 2 a.m.(COLUMN)72(COLUMN)74 3 a.m.(COLUMN)72(COLUMN)71 4 a.m.(COLUMN)72(COLUMN)74 5 a.m.(COLUMN)70(COLUMN)79 6 a.m.(COLUMN)70(COLUMN)79 7 a.m.(COLUMN)69(COLUMN)81 8 a.m.(COLUMN)71(COLUMN)73 9 a.m.(COLUMN)75(COLUMN)64 10 a.m.(COLUMN)76(COLUMN)64 11 a.m.(COLUMN)79(COLUMN)58 12 noon(COLUMN)81(COLUMN)55 1 p.m.(COLUMN)84(COLUMN)50 2 p.m.(COLUMN)84(COLUMN)58 3 p.m.(COLUMN)86(COLUMN)50 4 p.m.(COLUMN)86(COLUMN)50 5 p.m.(COLUMN)86(COLUMN)50 6 p.m.(COLUMN)85(COLUMN)53(END TABLE) Temperatures ending 8 a.m. (EDT) Yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)81(COLUMN)60 Albuqerque(COLUMN)97(COLUMN)58 Amarillo(COLUMN)100(COLUMN)71 Anchorage(COLUMN)62(COLUMN)52 Asheville(COLUMN)79(COLUMN)62 Atlanta(COLUMN)88(COLUMN)68 Atlanta City(COLUMN)72(COLUMN)60 Austin(COLUMN)92(COLUMN)73 Baltimore(COLUMN)89(COLUMN)65 Billings(COLUMN)73(COLUMN)49 Birmingham(COLUMN)88(COLUMN)70 Bismarck(COLUMN)74(COLUMN)57 Boise(COLUMN)85(COLUMN)52 Boston(COLUMN)75(COLUMN)59 Brownsville(COLUMN)91(COLUMN)78 Buffalo(COLUMN)86(COLUMN)71 Burlington, VT.(COLUMN)84(COLUMN)61 Casper(COLUMN)85(COLUMN)51 Charleston, S.C.(COLUMN)86(COLUMN)73 Ch'eston, W.VA.(COLUMN)84(COLUMN)64 Charlotte, N.C.(COLUMN)83(COLUMN)67 Cheyenne(COLUMN)76(COLUMN)51 Chicago(COLUMN)91(COLUMN)72 Cincinnati(COLUMN)85(COLUMN)66 Cleveland(COLUMN)83(COLUMN)68 Columbia, S.C.(COLUMN)88(COLUMN)68 Columbus, Ohio(COLUMN)86(COLUMN)68 Dal.-Ft. Worth(COLUMN)96(COLUMN)74 Dayton(COLUMN)88(COLUMN)70 Denver(COLUMN)83(COLUMN)55 Des Moines(COLUMN)96(COLUMN)70 Detroit(COLUMN)87(COLUMN)67 Duluth(COLUMN)76(COLUMN)54 El Paso(COLUMN)106(COLUMN)59 Fairbanks(COLUMN)72(COLUMN)56 Fargo(COLUMN)77(COLUMN)58 Flagstaff(COLUMN)87(COLUMN)35 Great Falls(COLUMN)71(COLUMN)44 Hartford(COLUMN)84(COLUMN)55 Helena(COLUMN)68(COLUMN)43 Honolulu(COLUMN)87(COLUMN)75 Houston(COLUMN)90(COLUMN)77 Indianapolis(COLUMN)90(COLUMN)72 Jackson, Miss.(COLUMN)87(COLUMN)71 Jacksonville(COLUMN)93(COLUMN)69 Juneau(COLUMN)66(COLUMN)51 Kansas City(COLUMN)87(COLUMN)69 Las Vegas(COLUMN)103(COLUMN)74 Little Rock(COLUMN)77(COLUMN)68 Los Angeles(COLUMN)80(COLUMN)58 Louisville(COLUMN)86(COLUMN)70 Memphis(COLUMN)84(COLUMN)72 Miami Beach(COLUMN)86(COLUMN)80 Midland(COLUMN)102(COLUMN)69 Milwaukee(COLUMN)86(COLUMN)62 Mpls. St. Paul(COLUMN)79(COLUMN)60 Nashville(COLUMN)88(COLUMN)72 New Orleans(COLUMN)93(COLUMN)72 New York(COLUMN)79(COLUMN)63 Norfolk(COLUMN)84(COLUMN)62 North Platte(COLUMN)77(COLUMN)66 Oklahoma City(COLUMN)90(COLUMN)71 Omaha(COLUMN)88(COLUMN)64 Orlando(COLUMN)96(COLUMN)72 Philadelphia(COLUMN)81(COLUMN)59 Phoenix(COLUMN)108(COLUMN)75 Pittsburgh(COLUMN)81(COLUMN)61 Portland, M.E.(COLUMN)77(COLUMN)45 Portland, Ore.(COLUMN)80(COLUMN)58 Providence(COLUMN)80(COLUMN)54 Raleigh(COLUMN)85(COLUMN)66 Rapid City(COLUMN)76(COLUMN)54 Reno(COLUMN)88(COLUMN)63 Richmond(COLUMN)86(COLUMN)60 St. Louis(COLUMN)92(COLUMN)70 St. Prbg-Tampa(COLUMN)94(COLUMN)73 Salt Lake City(COLUMN)87(COLUMN)55 San Antonio(COLUMN)92(COLUMN)77 Sand Diego(COLUMN)71(COLUMN)63 San Francisco(COLUMN)57(COLUMN)53 San Juan, P.R.(COLUMN)87(COLUMN)78 St. Ste. Marie(COLUMN)76(COLUMN)40 Seattle(COLUMN)74(COLUMN)59 Shreveport(COLUMN)81(COLUMN)68 Sioux Falls(COLUMN)82(COLUMN)65 Spokane(COLUMN)78(COLUMN)55 Syracuse(COLUMN)80(COLUMN)59 Topeka(COLUMN)83(COLUMN)70 Tucson(COLUMN)104(COLUMN)68 Tulse(COLUMN)83(COLUMN)73 Washington(COLUMN)86(COLUMN)69 Wichita(COLUMN)86(COLUMN)71(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)T. Aberdeen(COLUMN)drizzle(COLUMN)1 p.m.(COLUMN)54 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Ankara(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)84 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)84 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)55 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Birmingham(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)52 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)104 Casablanca(COLUMN)cloudy(COLUMN)noon(COLUMN)70 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)52 Geneva(COLUMN)clear(COLUMN)1 p.m.(COLUMN)75 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)86 Lisbon(COLUMN)cloudy(COLUMN)noon(COLUMN)66 London(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)54 Madrid(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Maita(COLUMN)clear(COLUMN)1 p.m.(COLUMN)79 Manila(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)82 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)82 New Delhi(COLUMN)clear(COLUMN)5 p.m.(COLUMN)104 Nice(COLUMN)clear(COLUMN)1 p.m.(COLUMN)70 Oslo(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)77 Paris(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Peking(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Rome(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Sofia(COLUMN)storm(COLUMN)2 p.m.(COLUMN)68 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Sydney(COLUMN)cloudy(COLUMN)10 p.m.(COLUMN)61 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)88 Tokyo(COLUMN)rain(COLUMN)9 p.m.(COLUMN)64 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Vienna(COLUMN)clear(COLUMN)1 p.m.(COLUMN)77 Warsaw(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Achoulco(COLUMN)pt. cloudy(COLUMN)93(COLUMN)81 Barbados(COLUMN)pt. cloudy(COLUMN)86(COLUMN)75 Bermuda(COLUMN)pt. cloudy(COLUMN)84(COLUMN)75 Calgary(COLUMN)pt. cloudy(COLUMN)66(COLUMN)48 Culiacan(COLUMN)clear(COLUMN)95(COLUMN)77 Edmonton(COLUMN)clear(COLUMN)72(COLUMN)39 Kingston(COLUMN)clear(COLUMN)90(COLUMN)78 Montego Bay(COLUMN)clear(COLUMN)88(COLUMN)75 Mexico City(COLUMN)pt. cloudy(COLUMN)73(COLUMN)54 Monterrey(COLUMN)pt. cloudy(COLUMN)95(COLUMN)85 Montreal(COLUMN)rain(COLUMN)81(COLUMN)59 Nassau(COLUMN)pt. cloudy(COLUMN)88(COLUMN)77 Ottawa(COLUMN)rain(COLUMN)81(COLUMN)59 Regina(COLUMN)pt. cloudy(COLUMN)70(COLUMN)43 St. Kitts(COLUMN)cloudy(COLUMN)88(COLUMN)78 St. Thomas(COLUMN)clear(COLUMN)89(COLUMN)80 Toronto(COLUMN)cloudy(COLUMN)79(COLUMN)57 Vancouver(COLUMN)cloudy(COLUMN)70(COLUMN)55 Veracruz(COLUMN)cloudy(COLUMN)86(COLUMN)77 Winnipeg(COLUMN)cloudy(COLUMN)73(COLUMN)59(END TABLE)