I second what the previous two posters said. October weather in PA can be kinda iffy. It might be nice and warm, or it might be rather chilly. Most likely, it will be like violetpretty said - 60's, maybe low 70's. And like jess_pom said, pack layers and check the weather forecast if you can.
As for houses at UPenn, this is the list I found from the
UPenn Greek Life website.
UNIVERSITY OWNED/RELATED
Alpha Chi Omega 3906 Spruce Street
Alpha Tau Omega 225 S. 39th Street
Beta Theta Pi 3900 Spruce Street
Chi Omega 3926 Spruce Street
Delta Kappa Epsilon 307 S. 39th Street
Delta Phi 3627 Locust Walk
Delta Upsilon 3829 Walnut Street
Kappa Alpha Society 124 S. 39th Street
Kappa Sigma 3706 Locust Walk
Kappa Alpha Theta 130 S. 39th Street
Lambda Chi Alpha 128 S. 39th Street
Phi Delta Theta 3700 Locust Walk
Phi Kappa Psi 3934 Locust Walk
Pi Kappa Alpha 3916 Spruce Street
Psi Upsilon 250 S. 36th Street
Sigma Alpha Epsilon 3908 Spruce Street
Sigma Alpha Mu 3817 Walnut Street
Sigma Chi 3809 Locust Walk
Sigma Delta Tau 3833 Walnut Street
Sigma Kappa 3928 Spruce Street
Sigma Phi Epsilon 4028 Walnut Street
Tau Epsilon Phi 3805 Walnut Street
Zeta Beta Tau 235 S. 39th Street
Zeta Psi 3337 Walnut Street
PRIVATELY OWNED
Alpha Chi Rho 219 S. 36th Street
Delta Psi 3637 Locust Walk
Phi Kappa Sigma 3539 Locust Walk
Phi Sigma Sigma 4032 Walnut Street
Sigma Nu 3819 Walnut Street
LEASED HOUSES
Alpha Epsilon Pi 4039 Walnut Street
Alpha Phi 4045 Walnut Street
Delta Delta Delta 4044 Spruce Street
Pi Kappa Phi 4040-42 Walnut Street
Threaded Mode
