Weather update client in Clojure

;; Weather update client
;; Connects SUB socket to tcp://localhost:5556
;; Collects weather updates and finds avg temp in zipcode

(ns wuclient
(:require [zeromq.zmq :as zmq]
[clojure.string :as str]))

(defn message->temperature [socket]
(-> (zmq/receive-str socket)
(str/split #" ")
(#(Long/parseLong %))))

(defn -main [& args]
(println "Collecting updates from weather server…")
(let [filter (or (first args) "10001")
context (zmq/zcontext)]
(let [subscriber (doto (zmq/socket context :sub)
(zmq/connect "tcp://")
(zmq/subscribe filter))]
(let [times 10
temps (repeatedly times (partial message->temperature subscriber))
avg (int (/ (apply + temps) (count temps)))]
(printf "Average temperature for zipcode '%s' was %d\n" filter avg))
(finally (.destroySocket context subscriber) ;; close hangs the process
(.destroy context))))))