What is the meaning of this information provided by Air Traffic Control?
This is a METAR, a weather report. From the Wikipedia article:


  METAR is a format for reporting weather information. A METAR weather
  report is predominantly used by pilots in fulfillment of a part of a
  pre-flight weather briefing, and by meteorologists, who use aggregated
  METAR information to assist in weather forecasting.


The meaning of this METAR is:

Location: LTBA
Day of month: 16
Time: 21:20 UTC
Wind:  True direction = 030 degrees, Speed: 8 knots
Wind direction is variable between 360 and 080
Visibility: 10 km or more
Clouds: Broken sky , at 3500 feet above aerodrome level
Temperature: 06 degrees Celsius
Dewpoint: 02 degrees Celsius
QNH (Sea-level pressure): 1028 hPa
No significant changes expected in the near future


NOSIG means: No significant changes expected in the near future.

See this METAR-TAF decoder.