Correlation of weather and traffic accidents (timechart)

I have these data has anyone has any idea how to correlate the accidents with the weather (rain) ? I used these search source="ltaTraffic" Type="Accident" OR source="CurrentWeatherSG" current_summary="Rain" | . I have would like to display the count for accident against rain in a timechart (lines.)

<entry> <id>http://datamall.mytransport.sg/LTAoDataService.svc/IncidentSet(2889345)</id> <title type="text">(10/7)14:41 Accident in CTE Tunnel (towards AYE) before Outram Rd Exit. Avoid lane 3.</title> <summary type="text"></summary> <updated>2013-07-10T07:12:40Z</updated> <author> <name/> </author> <d:incidentid m:type="Edm.Int32">2889345</d:incidentid> <d:message>(10/7)14:41 Accident in CTE Tunnel (towards AYE) before Outram Rd Exit. Avoid lane 3.</d:message> <d:latitude m:type="Edm.Double">1.2871711725850461</d:latitude> <d:longitude m:type="Edm.Double">103.84022565112657</d:longitude> <d:type>Accident</d:type> <d:summary m:null="true"/> <d:createdate m:type="Edm.DateTime">2013-07-10T07:09:47.15</d:createdate> <d:distance m:type="Edm.Double">0</d:distance> </entry>

and these

<d:nowcastid m:type="Edm.Int32">1317322</d:nowcastid> <d:area>Upper Bukit Timah</d:area> <d:condition>Partly Cloudy</d:condition> <d:latitude m:type="Edm.Double">1.356084</d:latitude> <d:longitude m:type="Edm.Double">103.768873</d:longitude> <d:summary>Partly Cloudy</d:summary> <d:distance m:type="Edm.Double">0</d:distance>