Washington: Today - Variably cloudy, but rain likely by tonight, high in the upper 60s, low near 50. The chance of rain is 40 per cent today and 60 per cent tonight. Thursday - Rain, high in mid 60s.

Maryland and Virginia: Today - Variably cloudy, but rain likely by tonight, highs from the upper 50's to the 60s, lows from the low 40s to near 50. Thursday - Rain, highs from the low 50's to the 60s.

West Virginia: Today - Rain, highs from the mid 50s to the mid 60s, lows from the mid 30s to the 40s. Thursday - Rain ending, highs from the mid 40s to the mid 50s.

Lower Potomac and Chesapeake Bay: Today - Variably Cloudy, but rain likely by tonight. Visibility will be more than 5 miles, dropping to less than 2 miles in rain. Wind will be from the southwest at from 15 to 20 knots today, but up to 25 knots tonight. Waves in unprotected waters will be from 2 to 3 feet.

Extended Area Forecast for Friday through Sunday: Chance of showers in the mountains on Friday, fair through the remainder of the period. Highs will be from the mid to upper 50s, lows from the 30s to the low 40s. Normal Washington temperatures for the period are a high of 56 and a low of 38.

The National Weather Forecast for today - Rain with snow in the mountains, will extend from the northern third of the Pacific Coast into northwestern Montana. Showers will also reach from New England through North Carolina, across the Great Lakes and the Ohio Valley into the lower Mississippi Valley. Temperatures will be mild from the southern two-thirds of the Mississippi Valley across the OhioValley to the Atlantic Coast, aswell as over much of the Southwest. Temperatures elsewhere will remain seasonably cool and occasionally cold.

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 2 p.m. to 3 p.m. period was 9 for the pollutant, photochemical oxidants. Index values between zero and 24 indicate good air quality.When the index exceeds 100 the air is considered very unhealthy and individuals with lung, heart and eve ailments are urged to restrict their activity. The forecast for today indicates that the air quality will be good.

The National Weather Service forecasts the Potomac River stage at Little Falls should be near 4.1 feet today.

Washington data at 8 p.m. (EDT) yesterday: Highest temperature since 8 a.m. yesterday, 58 degrees at 2:40 p.m. Lowest temperature since midnight, 36 degrees at 6:30 a.m. Excess of temperature since Nov. 1, 100 degrees. Excess of temperature since Jan. 1, 523 degrees. Record high temperature for today, 76 degrees in 1928. Record low temperature for today, 19 degrees in 1933. Relative humidity: Maximum, 67 per cent at 4 a.m.; Minimum, 40 per cent at 3 p.m. Excess of precipitation since Nov. 1, 82 inches. Deficiency of precipitation since Jan. 1, 5.46 inches. Highest observed wind since 8 a.m. 10 miles per hour from the southsoutheast at 9 a.m. Peak gust since 8 a.m., 14 miles per hour from the southwest at 8:22 a.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 mid.(COLUMN)45(COLUMN)42 1 a.m.(COLUMN)44(COLUMN)45 2 a.m.(COLUMN)43(COLUMN)49 3 a.m.(COLUMN)41(COLUMN)55 4 a.m.(COLUMN)38(COLUMN)67 5 a.m.(COLUMN)37(COLUMN)64 6 a.m.(COLUMN)38(COLUMN)62 7 a.m.(COLUMN)37(COLUMN)67 8 a.m.(COLUMN)40(COLUMN)62 9 a.m.(COLUMN)44(COLUMN)51 10 a.m.(COLUMN)47(COLUMN)50 11 a.m.(COLUMN)50(COLUMN)48 12 noon(COLUMN)53(COLUMN)47 1 p.m.(COLUMN)53(COLUMN)45 2 p.m.(COLUMN)55(COLUMN)47 3 p.m.(COLUMN)58(COLUMN)40 4 p.m.(COLUMN)58(COLUMN)42 5 p.m.(COLUMN)55(COLUMN)51 6 p.m.(COLUMN)54(COLUMN)55 7 p.m.(COLUMN)52(COLUMN)61(END TABLE) Temperatures ending 8 a.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)37(COLUMN)20 Albuquerque(COLUMN)63(COLUMN)33 Amarillo(COLUMN)73(COLUMN)32 Anchorage(COLUMN)21(COLUMN)11 Asheville(COLUMN)56(COLUMN)25 Atlanta(COLUMN)59(COLUMN)36 Atlantic City(COLUMN)41(COLUMN)36 Austin(COLUMN)72(COLUMN)57 Baltimore(COLUMN)49(COLUMN)33 Billings(COLUMN)55(COLUMN)36 Birmingham(COLUMN)60(COLUMN)37 Bismarck(COLUMN)52(COLUMN)25 Boise(COLUMN)50(COLUMN)44 Boston(COLUMN)43(COLUMN)33 Brownsville(COLUMN)73(COLUMN)64 Buffalo(COLUMN)36(COLUMN)34 Burlington(COLUMN)31(COLUMN)21 Casper(COLUMN)49(COLUMN)35 Charleston, S.C.(COLUMN)55(COLUMN)45 Charlest'n, W.Va.(COLUMN)45(COLUMN)34 Charlotte(COLUMN)55(COLUMN)36 Cheyenne(COLUMN)56(COLUMN)39 Chicago(COLUMN)53(COLUMN)42 Cincinnati(COLUMN)52(COLUMN)42 Cleveland(COLUMN)38(COLUMN)34 Columbia, S.C.(COLUMN)58(COLUMN)26 Columbus(COLUMN)43(COLUMN)33 Dal.-Ft. Worth(COLUMN)73(COLUMN)55 Dayton(COLUMN)50(COLUMN)35 Denver(COLUMN)65(COLUMN)48 Des Moines(COLUMN)60(COLUMN)37 Detroit(COLUMN)35(COLUMN)30 Deluth(COLUMN)38(COLUMN)34 El Paso(COLUMN)69(COLUMN)35 Fairbanks(COLUMN)-2(COLUMN)-9 Fargo(COLUMN)34(COLUMN)24 Flagstaff(COLUMN)65(COLUMN)26 Great Falls(COLUMN)54(COLUMN)30 Hartford(COLUMN)40(COLUMN)25 Helena(COLUMN)54(COLUMN)34 Honolulu(COLUMN)86(COLUMN)76 Houston(COLUMN)72(COLUMN)65 Indianapolis(COLUMN)59(COLUMN)48 Jackson, Miss.(COLUMN)69(COLUMN)40 Jacksonville(COLUMN)66(COLUMN)38 Juneau(COLUMN)40(COLUMN)36 Kansas City(COLUMN)61(COLUMN)50 Las Vegas(COLUMN)76(COLUMN)47 Little Rock(COLUMN)69(COLUMN)51 Los Angeles(COLUMN)77(COLUMN)54 Louisville(COLUMN)57(COLUMN)46 Memphis(COLUMN)68(COLUMN)44 Miami Beach(COLUMN)73(COLUMN)63 Midland-Odessa(COLUMN)71(COLUMN)50 Milwaukee(COLUMN)46(COLUMN)37 Mpls-St. Paul(COLUMN)44(COLUMN)35 Nashville(COLUMN)62(COLUMN)43 New Orleans(COLUMN)69(COLUMN)45 New York(COLUMN)40(COLUMN)38 Norfolk(COLUMN)49(COLUMN)37 North Platte(COLUMN)64(COLUMN)29 Oklahoma City(COLUMN)72(COLUMN)59 Omaha(COLUMN)59(COLUMN)38 Orlando(COLUMN)76(COLUMN)51 Philadelphia(COLUMN)42(COLUMN)34 Phoenix(COLUMN)86(COLUMN)56 Pittsburgh(COLUMN)35(COLUMN)30 Portland, Me.(COLUMN)38(COLUMN)17 Portland, Ore.(COLUMN)53(COLUMN)43 Providence(COLUMN)40(COLUMN)28 Raleigh(COLUMN)51(COLUMN)32 Rapid City(COLUMN)58(COLUMN)37 Reno(COLUMN)64(COLUMN)26 Richmond(COLUMN)53(COLUMN)33 St. Louis(COLUMN)66(COLUMN)55 St. P'bg-Tampa(COLUMN)72(COLUMN)52 Salt Lake City(COLUMN)56(COLUMN)42 San Antonio(COLUMN)75(COLUMN)60 San Diego(COLUMN)70(COLUMN)56 San Francisco(COLUMN)66(COLUMN)54 San Juan(COLUMN)87(COLUMN)74 St. Ste. Marie(COLUMN)35(COLUMN)33 Seattle(COLUMN)53(COLUMN)42 Shreveport(COLUMN)74(COLUMN)47 Sioux Falls(COLUMN)45(COLUMN)29 Spokane(COLUMN)50(COLUMN)35 Syracuse(COLUMN)36(COLUMN)26 Topeka(COLUMN)61(COLUMN)38 Tucson(COLUMN)80(COLUMN)50 Tulsa(COLUMN)72(COLUMN)57 Washington(COLUMN)49(COLUMN)36 Wichita(COLUMN)62(COLUMN)41(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)45 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)46 Ankara(COLUMN)pt. cldy(COLUMN)3 p.m.(COLUMN)54 Athens(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)63 Auckland(COLUMN)clear(COLUMN)mid.(COLUMN)50 Berlin(COLUMN)rain(COLUMN)1 p.m.(COLUMN)46 Birmingham(COLUMN)clear(COLUMN)1 p.m.(COLUMN)43 Brussels(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)45 Casablanca(COLUMN)pt. cldy(COLUMN)noon(COLUMN)66 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)45 Dublin(COLUMN)clear(COLUMN)1 p.m.(COLUMN)41 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)46 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)66 Lissbon(COLUMN)clear(COLUMN)noon(COLUMN)63 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)46 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)61 Malta(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68 Manila(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)81 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)37 New Delhi(COLUMN)clear(COLUMN)5 p.m.(COLUMN)79 Nice(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)68 Oslo(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)41 Paris(COLUMN)rain(COLUMN)1 p.m.(COLUMN)46 Peking(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)46 Rome(COLUMN)pt. cldy.(COLUMN)1 p.m.(COLUMN)68 Saigon(COLUMN)clear(COLUMN)8 p.m.(COLUMN)79 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)52 Stockholm(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)43 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)59 Tel Aviv(COLUMN)pt. cldy(COLUMN)2 p.m.(COLUMN)72 Tokyo(COLUMN)pt. cldy(COLUMN)9 p.m.(COLUMN)59 Tunis(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)68 Vienna(COLUMN)clear(COLUMN)1 p.m.(COLUMN)50 Warsaw(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)46(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt. cldy(COLUMN)90(COLUMN)75 Barbados(COLUMN)fair(COLUMN)85(COLUMN)79 Bermuda(COLUMN)pt. cldy(COLUMN)75(COLUMN)66 Bogota(COLUMN)pt. cldy(COLUMN)65(COLUMN)52 Calgary(COLUMN)clear(COLUMN)48(COLUMN)25 Culiacan(COLUMN)pt. cldy(COLUMN)94(COLUMN)66 Edmonton(COLUMN)clear(COLUMN)48(COLUMN)19 Havana(COLUMN)fair(COLUMN)81(COLUMN)70 Kingston(COLUMN)cloudy(COLUMN)88(COLUMN)75 Montego Bay(COLUMN)pt. cldy(COLUMN)90(COLUMN)74 Mexico City(COLUMN)haze(COLUMN)70(COLUMN)45 Monterrey(COLUMN)cloudy(COLUMN)77(COLUMN)58 Montreal(COLUMN)cloudy(COLUMN)32(COLUMN)28 Nassau(COLUMN)fair(COLUMN)76(COLUMN)66 Ottawa(COLUMN)snow(COLUMN)32(COLUMN)25 Regina(COLUMN)clear(COLUMN)52(COLUMN)30 St. Kitts(COLUMN)pt. cldy(COLUMN)89(COLUMN)73 St. Thomas(COLUMN)pt. cldy(COLUMN)87(COLUMN)74 Toronto(COLUMN)clear(COLUMN)39(COLUMN)34 Vancouver(COLUMN)rain(COLUMN)52(COLUMN)39 Veracruz(COLUMN)fair(COLUMN)81(COLUMN)62 Winnipeg(COLUMN)cloudy(COLUMN)36(COLUMN)27(END TABLE)