As a Seattle Sounders fan, you could be forgiven for thinking that the team hasn't played a dry game all year. I can't remember the last time I came home from a match and didn't have to wring out my clothes. Add in the monsoon game in Philadelphia and it seems like the Sounders are bringing rain wherever they go.
To test that theory out, I aggregated the weather data for every match in MLS so far this season. I added up the daily precipitation values for each team as well as the average temperature on game days. And it shouldn't come as any surprise that the Sounders lead the league in wetness. They've played in an accumulated 4.8 inches of rain so far this season, including 1.57 at home and 3.23 away. To be fair, those numbers are highly skewed by the Union game. On April 16, the Philadelphia region enjoyed a record-breaking 2.27 inches of rain. To take some of that skew out I also calculated the number of 'wet' days, which are days with at least 0.2 inches of rain. The Sounders also lead in that category. The full table is behind the cut.
| Team | Home Wet |
Home Precip |
Home Temp |
Away Wet |
Away Precip |
Away Temp |
Total Wet |
Total Precip |
Total Temp |
|---|---|---|---|---|---|---|---|---|---|
| seattle sounders fc | 3 | 1.57 | 51.14 | 3 | 3.23 | 52.66 | 6 | 4.8 | 51.84 |
| san jose | 2 | 1.12 | 55.83 | 2 | 2.61 | 54.5 | 4 | 3.73 | 55.3 |
| toronto fc | 4 | 2.95 | 44.57 | 1 | 0.54 | 55.6 | 5 | 3.49 | 49.16 |
| los angeles | 1 | 1.22 | 62 | 3 | 1.45 | 50.25 | 4 | 2.67 | 55.28 |
| philadelphia union | 1 | 2.31 | 51.83 | 1 | 0.29 | 62 | 2 | 2.6 | 55.9 |
| new york red bulls | 2 | 2.34 | 59 | 0 | 0 | 56.2 | 2 | 2.34 | 57.6 |
| new england | 2 | 0.93 | 46.33 | 1 | 1.37 | 58 | 3 | 2.3 | 51.63 |
| chicago | 0 | 0.08 | 45 | 2 | 1.99 | 56.16 | 2 | 2.07 | 51.7 |
| dc united | 2 | 1.05 | 56.83 | 1 | 0.81 | 48.5 | 3 | 1.86 | 53.5 |
| portland timbers | 2 | 1.28 | 50 | 1 | 0.53 | 47.4 | 3 | 1.81 | 48.7 |
| columbus | 2 | 0.88 | 46.2 | 2 | 0.86 | 55.2 | 4 | 1.74 | 50.7 |
| vancouver whitecaps | 2 | 1.68 | 45.33 | 0 | 0.01 | 54 | 2 | 1.69 | 49.27 |
| colorado | 0 | 0.12 | 50.6 | 2 | 0.98 | 64.14 | 2 | 1.1 | 58.5 |
| real salt lake | 0 | 0.01 | 54.5 | 1 | 1.05 | 56.25 | 1 | 1.06 | 55.37 |
| kansas city | 0 | 0 | 0 | 2 | 0.99 | 50.5 | 2 | 0.99 | 50.5 |
| chivas usa | 0 | 0 | 59.2 | 1 | 0.89 | 53 | 1 | 0.89 | 56.1 |
| fc dallas | 1 | 0.42 | 69.71 | 1 | 0.24 | 49.4 | 2 | 0.66 | 61.25 |
| houston | 0 | 0 | 72 | 0 | 0.12 | 57 | 0 | 0.12 | 65.18 |
Here's the log of raw data for the Sounders. The format is date, home team, away team, precipitation (in inches), and mean temperature (in Fahrenheit).
2011-3-15 seattle-sounders-fc los-angeles 0.43 50 2011-3-19 new-york-red-bulls seattle-sounders-fc 0.00 49 2011-3-25 seattle-sounders-fc houston 0.11 47 2011-4-2 san-jose seattle-sounders-fc 0.00 58 2011-4-9 seattle-sounders-fc chicago 0.00 48 2011-4-16 philadelphia-union seattle-sounders-fc 2.27 50 2011-4-22 colorado seattle-sounders-fc 0.00 49 2011-4-30 seattle-sounders-fc toronto-fc 0.17 50 2011-5-4 dc-united seattle-sounders-fc 0.56 54 2011-5-7 columbus seattle-sounders-fc 0.40 56 2011-5-14 seattle-sounders-fc portland-timbers 0.52 57 2011-5-21 seattle-sounders-fc kansas-city 0.10 52 2011-5-25 seattle-sounders-fc fc-dallas 0.24 54
It's also fair to wonder how much this has impacted the Sounders' offense. Seattle isn't a particularly direct team. When they do play long balls they rarely go anywhere dangerous (although Kasey Keller gets an occasional assist) and they still haven't figured out good free kick or corner service. And with the losses of Steve Zakuani and Sanna Nyassi on the wings they aren't really a fast dribbling team either. That leaves them as a technical offense that uses a lot of well-weighted passes to penetrate a defense. But while you can play direct or with speed in wet conditions, a wet surface can play havoc with a technical game. That was apparent in last night's match against FC Dallas when an endless number of attempted passes went long. From the data above you can see that some of the best Seattle home performances (against Toronto and Houston, for example) have been some of the drier games. The only home game with no precipitation at all was against Chicago, which was another win. In fact, the Sounders have not won on a wet day all season. Their four victories have all come on days with less than 0.2 inches of rain, including Chicago (0.0), Colorado (0.0), Toronto (0.17), and Kansas City (0.1).
When I get some time I'll look at some historical data to see if wet conditions depress offensive output in general. It's entirely possible that the Sounders would see some offensive improvement as much from drier conditions as from improving health.